JSH: How can I make my lessons interesting and meaningful to the students?
sanboz
teaching is an art form. Others believe that one has to love teaching in
order to make it a lifelong commitment. The latter is true for me. I love to
teach, and I want my lessons to be interesting and meaningful to my
students. My experiences with different age groups have made this idea of a
meaningful and interesting lesson a burning desire for me to accomplish
within the confines of the curriculum.
I have taught for many years, in different countries, and at different grade
levels. All through these years, the same questions keep coming to mind.
How can I make my lessons interesting and meaningful to the students?
What kinds of hands-on- materials would be most useful and effective for the
learners to comprehend, considering the enormous amount of
materials/activities available to both teachers and students today?
Is it possible for my students to design experiments, write equations for
the chemical reactions, and create molecular descriptions of a future event
based on current evidence or past experience?
Based on these experiences, I decided to develop a curriculum that will
enable my students to understand the periodic table, elements, and
compounds. If everything we see around us is either an element or a
compound, then in order to understand the world, as we know it, we have to
somehow engender in the students a mode of thought that sees things at that
level. When students drink a glass of water for example, do they have a
blank spot in their minds when the materials they are devouring are
slithering down their little throats or do they see little models of the
water molecule, in constant motion of course, in fact in enough motion to be
in the liquid phase? And do they see the molecular interactions between the
water molecules, with the negative pole of one little molecule attracting
the positive pole of another, so much so in some cases that water actually
ionizes itself, constantly forming hydronium and hydroxide ions and then
just as constantly forming water molecules again depending on the proximity
of the molecules? In this curriculum unit, I want to explore how we can
create scientifically literate thoughts in the minds of our students and how
we can get them thinking at the atomic level.
Learning to see the nano-world, the world of the very small, has never been
more necessary than at this particular historical conjunction. With
Hollywood making movies about the nanobots, instilling fear of what might
certainly prove to be the salvation of our planet, the study of the
atom-to-atom interactions must at some point be understood and mastered if
we are to have the means to control our destiny. It becomes all the more
important for teachers to address this aspect of the human conversation,
demystifying and demythologizing the study of the atoms and molecules that
make up our material environment.
This year I have been a participant in the Houston Teacher's Institute (HTI)
seminar "Chemistry through the Ages." In the seminar we have attempted to
peer into the discussion of
what the universe is made of, starting with the Greeks-Democritus and his
teacher Leucippus, who first proposed in writing that has been preserved,
the concept of the atom. It is startling to look back as these incredibly
perceptive natural philosophers as they used human reason to try to explain
the world they see around them. It is amazing to know that their thinking
was not influenced by a science class in school in which the teachers tried
to get them to believe in atoms. They just deduced, using logic and their
own experience, that the world must be composed of tiny basic particles that
cannot be further divided without losing something essential.
This notion was debated, ignored, pondered, and finally in the 1600's,
experimented with when John Dalton finally said, "Darn. My laboratory
experiments tell me that Democritus was right on the money." But again,
Dalton was experimenting and thinking in a relative scientific void compared
to the climate our students are privileged to be immersed in. Later in the
early 1900s we find ourselves having to again make a radical leap in our
understanding as J. J. Thomsen discovers a disturbingly negative little
something (electron) that streams out of the little solid marble that
Democritus and Dalton envisioned. Then Rutherford stuns the world when his
alpha particles whiz right through the thin gold foil instead of being
deflected like Thomsen's plum pudding would have done if it indeed were plum
pudding. Shazzam, we undergo a paradigm shift in our thinking about the
atom, as it suddenly becomes mostly empty space, a far cry from what
Democritus, Dalton and Thomsen saw. After Bohr got through with that empty
space it was divided into distinct energy levels and after de Broglie got
through with the electron, it was never in any one spot but was instead a
negative cloud with only probabilities to describe it. The atom that our
students learn then, is the result of a long process of trial and error, a
model that is still being revised and changed but which now explains more
neatly the things we see happening in our laboratories. And, seeing things
happen in the laboratory that can then be explained using the models is what
this unit purports to do.
Students will learn the specific uses of the elements, the dates of their
discovery, and the probable physical and chemical changes that may occur
when these elements are placed in close proximity to one another. The
lessons will be suitable for middle school students, especially the sixth
graders. This is the age when children seem to develop a lack of interest in
academics, and science in particular. Either that or they suddenly develop
inordinate interest in the social aspects of being human so that all else is
pushed aside. The objective of this unit is to present lessons on elements,
compounds, and chemical reactions that show a relationship amongst these
topics in a fun and interesting way. Experimentation with household items
that will demonstrate the extent of chemical reactions around us will be
explored at a greater length. Making chemical reactions real instead of an
abstract concept will be a major focus of this curriculum unit.
UNIT BACKGROUND
Because of the work we did in the HTI seminar with Dr. Scott Perry
(University of Houston chemistry professor) studying the developing
understanding of chemistry through the ages, I am inspired to help my
students investigate the nature of elements, their arrangement in the
periodic table, the extent of their abundance, their difference from
compounds and mixtures, and their role in chemical reactions.
The students will investigate the year elements were discovered, their uses,
and how they are arranged in the periodic table. They will identify some
familiar compounds and their constituent elements. This curriculum unit will
help my sixth grade students understand the historical development of our
knowledge of the elements, how we have learned to understand elements
combining to form compounds, and how compounds and elements interact to
create the phenomena we witness in our daily lives. The curriculum will also
be an excellent tool for any middle school science teacher who is interested
in a new and innovative method of teaching physical and chemical changes,
chemical reactions, and the discovery of elements. The students will create
a data table with the names of the elements, dates of discovery, uses of
these elements, and plot a graphical representation of the period that the
elements were discovered. The graph will be an additional tool to address
different types of learners. Teachers who want to avail themselves of the
books cited in the bibliography will find these sources rich in narratives
that give life to what could otherwise be dry lists of facts. In the course
of the HTI seminar we have read three books in particular which can help
teachers develop a more narrative approach to the teaching of chemistry
facts. (See bibliography)
One may want to know why it is important to know when these elements were
discovered. Today's students want to accomplish tasks in a fast and easy
manner. Anything that takes a while to accomplish is considered to be a
waste of time. I see this behavior almost everyday in my laboratory.
Students want to know why they should do three trials to obtain a valid
result; why can't they do it once or twice; why do they need three trials
per test, always why, why, why? Students need to know the many, many, many
years of trials, accidents and lucky guesses that have preceded our current
volume of knowledge about the make-up of the universe. The students need to
know that some elements such as carbon and sulfur were known and used by
ancient civilizations. The Iron Age and the Bronze Age are named for the
elements and compounds that helped shaped the events we are taught as
history.
In this unit, the students will also use analytical and qualitative skills,
inferences and predictions, creativity, and problem-solving skills to
investigate elements in each group of the periodic table. The students will
work in groups of eight to investigate elements, when they were discovered,
their physical and chemical properties, and some common reactions. They will
also be able to identify constituent elements from the reactions.
Overview of Elements, the Periodic Table, Compounds, Mixtures, and Chemical
Reactions
Elements are found almost everywhere, in the ocean, in the air, the earth,
and the body. An element is a pure substance that is made of only one kind
of atom. An atom is a tiny structure found in all matter. Matter is anything
that has mass and occupies space. Most substances contain many different
atoms. Elements contain only one kind of atom. The most abundant element in
the air is nitrogen, in the earth is oxygen, and in the body is hydrogen.
Elements found in the body are hydrogen, oxygen, carbon, nitrogen, and other
trace elements. In the Periodic Table, elements are arranged in horizontal
rows and vertical columns. The elements in the horizontal rows are known as
periods while the elements in the vertical columns are known as groups or
families. The horizontal rows represent electron energy levels, and the
vertical columns represent the chemical properties of the elements. Elements
are also grouped as metals, non-metals, and metalloids. Metals are elements
that have the properties of luster, malleability, ductility, and
conductivity. Nonmetals do not have the properties of luster, malleability,
ductility, and conductivity. Metalloids are elements that have some
properties of both metals and nonmetals. The type of information available
from the periodic varies depending on the version; however, each table has
the element name, symbol, the atomic number, and the atomic mass. A symbol
identifies a single element, the atomic number equals the number of protons,
and the mass number equals the number of protons plus neutrons. The number
of electrons equals the number of protons. An atom is the smallest unit of
an element. It consists of three particles, namely, protons, neutrons, and
electrons. The nucleus of the atom is made of protons and neutrons while the
electrons move around rapidly in the space outside the nucleus.
Chemists use the periodic table to determine which elements can combine and
in what proportions. They also use the periodic table to determine which
elements have similar properties. Chemists can use this information to help
manufacturers determine how to improve their products and processes. For
example, the use of helium instead of hydrogen in dirigibles provides
safety.
Two or more elements combine chemically to form a compound. Molecules are
two or more atoms joined together by chemical bonds. The atom can be the
same element or different elements. If the molecule is a combination of
different elements, it is a compound. Carbon dioxide (CO2) and sodium
chloride (NaCl) are compounds, while ozone (O3) is not. It is a molecular
form of the element oxygen.
Mixtures are made of two or more pure substances that are mixed together but
not chemically combined. Examples of mixtures are Italian dressing, pizza,
and fruit salads. In these examples, the ingredients are mixed together, but
they still maintain their separate identity. Mixtures are classified into
two groups namely heterogeneous and homogeneous. A heterogeneous mixture
means that no two parts are identical, for example, pizza and salad. A
homogeneous mixture occurs when different parts appear as one, but are not.
Some examples of homogeneous mixtures are milk, stainless steel, and
toothpaste. In homogeneous mixtures, particles are mixed together but are
not dissolved completely; they are known as colloids. Colloids are larger
than ordinary molecules but too small to be seen with ordinary eyes. Most
colloids appear cloudy. The table below shows some examples of colloids:
Type of ColloidExamples
Fog (Liquid in gas)Clouds
Smoke (Solid in gas)Smoke
Sol (Solid in a liquid)Paint
Foam (Gas in a liquid)Whipped cream
Emulsion (Liquid in a liquid)Mayonnaise
Gel (Liquid in a solid)Butter
Chemical reactions take place when bonds between atoms break and form one or
more new substances. An equation describes a chemical reaction using symbols
and formulas. The reactants are on the left of the equation while the
product(s) are written on the right of the equation. Chemicals are reacting
if there is evidence such as color change, production of a gas, and odor.
New substances are created when chemicals react. A change in temperature
indicates that energy is being released or used as new substances are
formed. Reactants are chemicals that take part in chemical reactions, while
products are the new substances that form as a result of the chemical
reactions. An endothermic reaction is a reaction in which energy is
absorbed. An endothermic reaction feels cool because heat energy from the
hand is absorbed by the reaction. An exothermic reaction is a reaction in
which heat energy is released.
A chemical equation may be a synthesis reaction, a decomposition reaction,
or a replacement reaction. In a synthesis reaction, two or more substances
combine to form a new substance. Synthesis reactions happen around us
everyday. When fire burns, rust forms, and silver tarnishes, synthesis
reactions have taken place. Burning of a wooden splint is a chemical
reaction of a fuel and oxygen. Heat and light are always produced in this
synthesis reaction. In decomposition reaction, a compound breaks down to
form one or more simpler substances. This reaction occurs everyday, for
example, when you take a cap off a bottle of sprite or any other soda,
bubbles rise quickly to the top. Carbonic acid breaks down into carbon
dioxide and water. Chemical bonds are the forces that hold the different
substances of a compound together. These bonds are broken when the
attracting forces are broken through the use of energy.
Replacement reactions may be a single replacement reaction or double
replacement reaction. A single replacement reaction happens when one element
replaces another in a compound while in a double replacement reaction two
elements or compounds trade places and a precipitate, water or gas, forms. A
precipitate is an insoluble solid formed in the solution.
A chemical reaction is also known as a chemical change. In a chemical
change, a new substance is produced. Energy changes always accompany
chemical changes. Some examples of chemical changes are:
Hydrochloric acid reacts with sodium hydroxide to produce a salt, water, and
heat.
Potassium chlorate decomposes to potassium chloride and oxygen gas.
Iron rusts.
Milk sours.
Wood rots.
Acid on limestone produces carbon dioxide gas.
A physical change involves a change in form while the original substance
still exists. Some examples of physical changes are:
Sodium hydroxide dissolves in water.
A pellet of sodium is cut in two.
Liquid is heated and changed into vapor.
Ice melts.
IMPLEMENTATION STRATEGIES
The students will work in groups to investigate the following:
Elements and the year the elements were discovered, uses of these elements,
and the arrangement of elements in the periodic table.
Each group will be given the following names: Group 1 - Alkalis (he Alkali
Metal Family - Group 1 Elements), Group 2 - Earth Metals (The Alkaline Earth
Metal Family - Group 2), Group 3 - Transitionals (The Transition Elements
Family - Group 3- 12), Group 4- The BCNO (The Boron, Carbon, Nitrogen,
Oxygen - Group 13- 16), Group 5- Halogens (The Halogen Family - Group 17),
Group 6- Nobles (The Noble Gases - Group 18), Group 7 - Lanthanides, Group
8 - Actinides.
The students will make a list of elements and their discovery dates on a
table similar to the table shown on Appendix A.
The data on the date of discovery of elements will be used to plot a bar
graph that shows how many elements were discovered within a certain period.
Is it important for the students to know when elements were discovered? I
think it is important because students usually search for an easy route to
solve problems; therefore, if they discover through their research that the
discovery of elements were not made in a day, maybe they will be more
patient during their lab investigations. Every teacher wants to cultivate
the right attitude to their students, in this case, the scientific method of
investigation and conducting experiments, so knowing when elements were
discovered and their uses will add a wealth of knowledge to any middle
school students, especially my six graders.
The students will also use a table to group substances into elements,
compounds, and mixtures. The table should be similar to the one shown below:
ElementsCompoundsMixtures
Pure
One kind of atom
Can be separated in nuclear reactions
Examples: Gold (Jewelry) and Aluminum (soda can)Pure
Two or more kinds of atoms chemically combined
Can be separated by chemical reactions
Examples: beaker of water (Hydrogen and Oxygen)
Iodized salt (Sodium and Chlorine)
Carbon Dioxide (Carbon and Oxygen)Not pure
Two or more elements or compounds physically combined together
Can be separated in physical reactions
Examples: Italian Dressing and Dumpling Sauce
The table will also include equations for reactions and structural formulas.
The students will use Styrofoam balls and other tools to make molecular
structures.
The students will use many sources including books and the Internet to
research their elements. Based on their investigations, the students will
appreciate the role elements play in our daily lives.
Chemical reactions are the focal point of this unit; therefore, the students
will conduct experiments that demonstrate different types of reactions, such
as synthesis reactions, replacement reactions, and decomposition reactions,
and write equations for the reactions. They should also be able to identify
a reaction as exothermic or endothermic. In an endothermic reaction heat is
released during the process while heat is absorbed in an endothermic
reaction.
The project will end with a collage in which all the groups will work
together to create a periodic table with information compiled by individual
groups. The collage will be a replica of the periodic table, however,
without element names, symbols or atomic numbers. The only data on the table
will be the potential uses of the element in today's world. This will be the
highlight of the project because it will involve all the scientists (my
students) working together to create a periodic table that is unique,
beneficial, and meaningful to them.
Finally, each student will either write a song, a poem, or create a puzzle
about the periodic table using the element symbol, picture and any new
information that they have discovered during their investigation.
Lesson PlanS:
Lesson One: Discovery of Elements.
Objectives: The students will understand and appreciate the unique nature of
elements, the historical development of elements, the arrangement of
elements in the periodic table, and how elements play a role in our daily
lives.
Materials
Computer
Paper
Pencil
Graph paper
Procedure
Provide background information on an element.
Explain to the students that the periodic table is the most important tool
available to scientists especially chemists, because it provides a wide
range of information about natural and synthetic elements. At present, there
are 92 naturally occurring elements and 23 synthetic elements. These
elements are arranged in horizontal rows and vertical columns. The elements
in the horizontal rows are called periods while the vertical columns
elements are known as groups or families. The horizontal rows represent
electron energy level, and the vertical columns represent the chemical
properties of the elements. There are 7 periods and 18 groups or families,
which are numbered from left to right of the periodic table.
Allow the students to draw a table with three columns in their laboratory
book. The first column is titled "Element," the second column "Date of
Discovery," and the third "Use." (See Appendix A.)
Take the students to the library where they can use computers, books and
other resources to investigate elements. (See appendix for sample.)
After compiling the data, allow the students to plot a bar graph of the date
that the elements were discovered.
By the end of lesson one, the students should be able to compile a table of
elements, the date of discovery of these elements, uses of the elements, and
plot a graph that will demonstrate how many elements were discovered within
a given period.
Lesson Two: Chemical Reactions
Objective: To understand chemical reactions using household materials and
dilute acids.
In this lesson, chemical reactions will be explored with concrete examples
using common substances such as baking soda, salt, baking powder, vinegar,
laundry detergent, and chemicals, such as hydrochloric acid, sulfuric acid,
and chlorine. The students will have opportunity to discuss, write
equations, and make models.
Chemical reactions occur when bonds between atoms break and form one or more
new substances. A chemical reaction is described by an equation using
symbols and formulas. For example, calcium chloride reacts with sodium
bicarbonate (baking soda) to produce calcium bicarbonate and sodium
chloride. This is represented by the equation - CaCl2 + 2 NaHCO3 -> Ca(
HCO3)2 + 2 NaCl.
A chemical reaction is also known as a chemical change. In a chemical
change, a new substance is produced. Energy changes always accompany
chemical changes. Some examples of chemical changes are as follows: iron
rusts, milk sours, wood rots, potassium chlorate decomposes to potassium
chloride and oxygen gas.
A physical change involves a change in form, or phase, the original
substance still exists. Some examples of physical change are as follows:
sodium hydroxide dissolves in water, heated liquid changes into steam, and
ice melts into liquid.
Experiment
Question:
What species are involved in chemical reactions?
Materials:
Distilled white vinegar (5% aqueous solution of acetic acid - HC2H3O2)
Sanded magnesium ribbon (Mg)
Beaker
Graduated cylinder
Stirring rod
Triple beam balance (If using magnesium from a chemical supply store)
Science journal
Procedure:
Divide the class into 4 groups.
Give each group the above materials.
Measure 10mL of vinegar and pour it in a beaker.
Drop a piece of freshly sanded magnesium ribbon in the beaker of white
vinegar and stir with a stirring rod. (If magnesium from a chemical supply
lab is available, use a triple beam balance to measure 5g of magnesium.)
Record observation in your science journal. Draw and label the beaker of
vinegar and magnesium.
Write a chemical equation for this reaction. Label the reactants and the
products.
Safety Precaution:
Wear safety goggles
Do not taste or smell any substance.
Wipe spills as they happen.
Wash hands at the end of the activity.
Lesson Three: Types of Chemical Reactions
Objective: The students will explore different types of chemical reactions
through experimentation.
In this section, the teacher will give the students background information
on different types of chemical reactions. The students will be expected to
perform simple experiments that demonstrate each type of reaction in this
lesson and subsequent lessons.
Different Kinds of Chemical Reactions:
Synthesis Reaction - Two or more substances combine to form a new substance.
Synthesis reactions happen around us everyday. When rust forms or silver
tarnishes, synthesis reactions have taken place.
Decomposition Reactions - A compound breaks down to form one or more simpler
substances. This reaction occurs everyday, for example, when a cap is taken
off a bottle of sprite or any other soda, bubbles rise quickly to the top.
Carbonic acid breaks down into carbon dioxide and water.
Carbonic acid -> Carbon dioxide and Water
(H2CO3) - -> CO2 + H20
Replacement Reactions - It may be a single replacement reaction or double
replacement reaction. A single replacement reaction occurs when one element
replaces another in a compound, while in a double replacement reaction, two
elements or compounds trade places and a precipitate forms. The precipitate
may be water or gas.
Experiment One: Synthesis Reactions
Question: What will happen to a silver spoon if submerged in an egg yolk?
Hypothesis: (Allow the students to write their hypothesis.)
Sample hypothesis - If there is a chemical reaction between the silver spoon
and egg yolk, then a new substance should form.
Materials:
Egg
Silver spoon
Stop-watch
Beaker
Water
Laboratory notebook
Safety Precautions:
Wear goggles
Do not play with the egg.
Procedure:
Separate a yolk from an egg white and placed the yolk in a 100-mL beaker.
Place a clean silver spoon in the egg yolk and stir.
Allow the spoon to sit in the container for 30 minutes.
Remove the spoon in egg yolk, rinse with water, and observe what happened to
the spoon.
Record observations in your laboratory note book.
Conclusions: Answer the questions in your laboratory notebook.
What happened to the spoon in the egg yolk?
Was there a chemical reaction? If there was, what caused the chemical
reaction?
Is it possible to reverse the change? How?
Why does silver tarnish if left sitting for a long period of time? Is there
sulfur in the air?
Write an equation for this reaction.
Experiment Two: Decomposition Reaction
Objective: The students will understand that decomposition reactions involve
the breaking down of a compound to form one or more simpler substances.
Background Information:
Give the students an overview of the sugar molecule. Most students might not
know that sugar is composed of three different elements with 45 atoms in one
simple molecule. (Sugar molecule - C12H22O11) Sugar can be decomposed by
heating it.
Question: Does Sugar Break Down into it Constituents Elements When Heated?
Hypothesis: (Allow the students to state the hypothesis)
Materials:
Sugar
Test tube
Metal tong
Hot plate or Bunsen burner
Triple beam balance
Safety Precautions:
Do not eat the sugar
Use precaution when working with hot plate or Bunsen burner.
Procedure:
Measure 5g of sugar and place each 5g of sugar in two identical test tubes.
Place test tube A on the test tube rack.
Hold test tube B with a metal tong and heat the test tube carefully until
the sugar is completely black.
Observe test tubes A and B and record your observation.
Using a wooden splint, taste the burnt sugar. (Do not shallow it)
Conclusion:
Did the change in chemical composition affect the appearance or odor? Is it
still sugar?
Write a chemical equation for this reaction.
Experiment 3: Single Displacement Reactions
Objective:
The students will perform simple experiments that explain the process of
replacement reactions.
Background Information:
Remind the students that replacement reactions may be a single replacement
reaction or double replacement reaction. A single replacement reaction
occurs when one element replaces another in a compound, while a double
replacement reaction occurs when two elements or compounds trade places and
a precipitate is formed. The precipitate might be water or gas. A
precipitate is a solid in the solution that is not dissolved.
Materials:
3 Molar HCl (Hydrochloric acid) 20% solution
Copper (penny)
Zinc (galvanized nails are coated with zinc)
Magnesium (from a chemical supply store)
3 Test tubes (for each group)
Test tube rack (one for each group)
Goggles
Safety Precautions:
Wear goggles.
Do not touch the acid.
Report any spills to the teacher. Do not attempt to clean the spill!
Procedure:
Divide the class into 4 groups.
Label the test tubes, A, B, and C. A - Copper, B -zinc, C- magnesium.
Measure 10mL of hydrochloric acid into the three test tubes.
Drop each metal into their respective test tube and observe.
Conclusion:
Did you observe any bubbles in the test tube?
Which test tube had more bubbles? Why?
In which test tube did you feel a slight warming of the test tube?
Write a singe replacement reaction equation for the 3 test tubes.
Lesson Four: Get To Know Your Elements (Gifted &Talented/Pre-Advanced
Placement Students)
Objective: The students will work independently to write a detail
description of five elements and how they are used today.
This section will be devoted to the detailed discussion of the uses of
elements. The students are to use the resources in the library to
investigate the uses of their assigned elements. This is mainly for the
Gifted and Talented /Pre- Advanced Placement students.
Each student should give a detailed description of at least 10 elements and
how they are used today. For example: Helium is used by astronomers to
eliminate space noise on their detectors. The students should describe how
it works. For example, how do astronomers use helium to eliminate space
noise? Helium was used to make the first gas lasers. Today gas lasers are
used in bar code scanners. Scuba divers use a mixture of oxygen and helium
to breathe. These are some of the uses for helium.
Procedure:
Following a class discussion of the uses of the different elements, the
class will construct a periodic table of the elements in which each element
is represented by a picture of its use. Chemical symbols will be added to
the picture for identification purposes.
Appendix A
ElementDate of DiscoveryUse
Phosphorus1669-It is used to make produce light, in glow in the dark clocks,
watches, and toys.
-It is used in television to make the image.
-It is used in laundry soaps and other detergents.
Platinum1700-It is used to make jewelry.
-It is used in refining oil, dental instruments, ceramics, electrical and
the electronic industries.
Nickel1751-It is used to make coins and nickels.
-It is used in magnets, heating elements in toasters and electric ovens.
-It is used in rechargeable batteries for calculators, computers, and
electric shavers.
Hydrogen1766-It is used to make ammonia, fertilizer, margarine and rocket
fuel.
Oxygen1774-It is used as liquid rocket fuel, makes ozone that protects us
from ultraviolet rays from the sun.
Potassium1807-It is used in explosives and gunpowder, to make batteries, and
liquid soap.
Iodine1811-It is used to make photo film, kill germs in small wounds.
-Iodine tablets are used to purify water.
Aluminum1825-It is used to make doors, screens, and window frames.
-It is used to make drink cans, pots, and pans.
-Aluminum is used in wires, reflectors, resistors, antennas, and solar
mirrors.
Indium1863-It is used in transistors and photocells.
Argon1894-Argon is used in fluorescent light bulbs.
Appendix B
Definition of Terms
Atom: The smallest unit of an element.
Atomic mass: Equals the number of protons plus neutrons.
Atomic number: Equals the number of protons.
Chemical bonds: Forces that hold atom together in molecules and keep ions in
place in solid ionic compounds.
Chemical equation: Is a statement that uses chemical formulas to express the
identities and quantities of the substances involved in a chemical or
physical change.
Chemical reaction (chemical change): A chemical reaction occurs when bonds
between atoms break and form one or more new substances.
Chemical formula: Scientific short way of describing the chemical content of
a substance. Number and letters stand for how many and what kinds of atoms
are in one molecule of the chemical. For example: In CO2, the C stands for
carbon and the O stands for Oxygen. There are two atoms of oxygen and one
atom of hydrogen.
Compound: Two or more elements combined chemically.
Constant: Conditions that an experimenter tries to keep from varying. (The
same)
Control: In a simple experiment, there is only one subject or group that
gets the experimental treatment. To better judge the results, the
experimenter may use a control group or subject. This group does not get the
experimental treatment but it is treated in every other way like the
experimental subject or group.
Colloids: Homogeneous mixture in which particles are mixed together but are
not dissolved.
Decomposition reaction: A compound breaks down to form one or more simpler
substances.
Dependent/Responding variable: When the experimenter changes something to
observe what happens in an experiment. What he or she changes may cause
something else to happen. Therefore, what happens as a result of the change
is known as the dependent or responding variable.
Electron: An electron carries a negative charge. Electrons move around
rapidly in the space outside the nucleus.
Element: An element is a pure substance that is made of only one kind of
atom.
Endothermic reaction: A reaction in which heat energy is absorbed.
Exothermic reaction: A reaction in which energy is released.
Experiment: An investigation made by changing or manipulating things. An
experiment is usually planned to answer a specific question, to solve a
problem, or to test a statement or hypothesis.
Heterogeneous mixtures: A mixture that has one or more visible boundaries
among its components.
Homogeneous mixtures (solution): A mixture that has no visible boundaries
among its components.
Hypothesis: A statement that explains what is to be tested, the purpose of
an investigation, and what the experimenter intends to prove or disprove.
Independent/Manipulated variable: An experimenter changes something in the
experiment to observe what will happen. The something that is changed is the
independent or manipulated variable.
Matter: Anything that has mass and occupies space.
Mixtures: Two or more substances that are mixed together but not chemically
combined.
Neutron: Protons and neutrons make up the nucleus of an atom. It carries no
charge, therefore, is neutral.
Precipitate: An un-dissolved solid in a solution.
Product: A new substance formed in a chemical reaction, the right side of
the yield sign in a chemical reaction.
Proton: Protons and neutrons make up the center or nucleus of an atom. The
proton carries a positive charge.
Reactants: The materials that react in a chemical equation, substances to
the left of the yield sign.
Solutions: Mixtures in which molecules are dissolved and uniformly dissolved
into one another.
Symbol: A symbol identifies a single element.
Variables: In a thing or pattern of things being observed, a change in a
dimension or a characteristic, a change in value or quantity.
Appendix C - Answer Key
Lesson Two: Chemical Reactions
Experiment One: Observations
When magnesium is placed in vinegar (vinegar contains 5% aqueous solution of
acetic acid - HC2H3O2), a chemical reaction occurs. Bubbles of hydrogen gas
are released and the strip of metal forms a new substance called magnesium
acetate.
Magnesium and acetic acid are the reactants, while magnesium acetate and
hydrogen gas are the products.
Mg + 2C2H4O2 Mg(C2H3O2) + H2
Magnesium Acetic Magnesium hydrogen
acetate (gas)
Lesson Three:
Experiment One: Synthesis Reaction
Conclusion
The spoon turned dark (tarnished).
Yes, the silver spoon reacts with the egg yolk that contain trace amount of
sulfur. This reaction produced the dark color.
Yes, an acid will react with sliver sulfide to reverse the dark color.
There are some traces of sulfur in the air because of pollution- this trace
element is responsible for the tarnishing of silver wares if left outside
for a longtime. Yes, there are traces of sulfur in the air because of
pollution.
Ag + S Ag2S
Silver Sulfur Silver sulfide
Experiment Two: Decomposition Reaction
Conclusion
Yes, the white powdered sugar turned black. This indicates that the sugar
broke down into carbon (the black material in the test tube) and water. The
water droplets are on the side of the test tube.
No, because the sugar has broken down into its constituent elements and
compound which is carbon and water.
C12H22O11 + heat 12C + 11H2O
Sugar Carbon Water
(glucose)
Experiment Three: Single Replacement Reactions
Yes
No bubbles form in the Beaker A (copper). A reasonable amount of gas is
produced in Beak B (Zinc) and while Beaker C (magnesium) produced bubbles of
gas. Beaker C feels warm because the reaction of magnesium and hydrochloric
acid is an exothermic reaction.
1. Cu + HCl CuCl2 + H
2. Zn + HCl ZnCl2 + H
3. Mg + HCl MgCl2 + H
ANNOTATED BIBLIOGRAPHY
Abbgy, Theodore S. Elements and the Periodic Table. Greensboro, NC: Mark
Twain Media/Carson-Dellosa Publishing Company, 2001.
This book gives a detailed description of the modern periodic table, the
arrangement of elements in the periodic table, and what things are made of.
Barber, Jacqueline. Chemical Reactions. Lawrence Hall of Science. University
of California, Berkeley, 2001.
This book outlines simple experiments that could be used to teach chemical
reactions.
Blashfield, Jean F. Sparks of Life - Calcium. Austin, Texas: Raintree
Steck-Vaughn Publishing, 1999.
This book provides the basic idea of the element calcium, its uses and
functions in the human body.
Farndon, John. Chemicals. New York: Marshall Cavendish Corporation, 2003.
This book provides a detail description of elements, compounds and chemical
reactions. The experiments given in the book reinforce an understanding of
the topics.
Farndon, John. The Elements--Oxygen. New York: Marshall Cavendish
Corporation, 1999.
The history of oxygen and properties of oxygen is discussed extensively in
this book.
Fitzgerald, Karen. The Story of Oxygen. New York: A Division of Grolier
Publishing, 1996.
This book describes the history of the elements oxygen and its chemistry,
how it works and its importance in our everyday activities.
Hill, Petrucci and Perry McGreary. General Chemistry, 4e. Upper Saddle
River, New Jersey: Prentice Hall, 2005.
This book provides a detail account of general chemistry with particular
reference to elements, their structure and functions.
Knapp, Brian. Hydrogen and the Noble Gases. Danbury, CT: Atlantic Europe
Publishing Company Limited, 2000.
This book gives an overview of the periodic table and a detail description
of the chemistry of hydrogen that is appropriate for a middle school
student.
Knapp, Brian. Sodium and Potassium. Danbury, CT: Atlantic Europe Publishing
Company Limited, 2000.
This book provides an overview of chemical reactions with particular
reference to sodium and potassium.
Le Couter, Penny and Jay Burreson. Napoleon's Buttons. New York: Penguin
Group Inc., 2004.
This book gives an account of the link between chemistry and nature. It goes
on to illustrate how a substance can be both harmful and beneficial
depending on the chemical combination and proportion of the reactants.
Newmark, Ann. Chemistry. New York: Dorling Kindersley, 1999.
This book provides in depth discussion of chemistry in nature as well as
works of modern alchemist like Ernest Rutherford.
Sparrow, Giles. The Element - Carbon. New York. Marshall Cavendish
Corporation, 1999.
This book gives a brief history of the discovery of carbon, the different
forms of carbon, and the role carbon plays in the greenhouse effect.
Uehling, Mark D. The Story of Hydrogen. New York: Grolier Publishing, 1995.
This book presents the properties of hydrogen in a story form. It is an
interesting resource for any middle school science class.
Uehling, Mark D. The Story of Carbon. New York: Grolier Publishing, 1995.
This book uses favorite children characters to describe the properties of
carbon.
Morris, Richard. The Last Sorcerer: The Path From Alchemy to the Periodic
Table. Washington D.C.: Joseph Henry Press, 2003.
This book gives the genesis of what we know today as scientific inquiry.
Louis Lavoisier performed several experiments that provided lasting and
verifiable proof of many chemical theories by measuring, examining and
recording data.
Silberberg, Martin. Chemistry: The Molecular Nature of Matter and Change.
New York: McGraw Hill Companies Inc., 2003.
This book gives detail examples of major classes of chemical reactions and
their molecular structures.
Strathem, Paul. Mendeleyev's Dream: The Quest for Elements . New York: The
Berkley Publishing Group, 2002.
This book outlines the historical perspective in the development of the
periodic table. It gives a detail explanation of how politics, and religion
affected scientists thought process during the early centuries.
Thomas, Moorman. How to Make Your Science Project Scientific. New York: John
Wiley & Sons, Inc. 2002.
This book gives a detail simple explanation on how to conduct a scientific
experiment.
Trombley, Linda. Mastering the Periodic Table. Portland, Maine: J. Weston
Walch Publisher, 2000.
This book explains the design, uses and complexities of the periodic table.
White, Larry. Water: Simple Experiments for Young Scientists. Brookfield,
Connecticut: The Millbrook Press, 1995.
This book provides age appropriate experiments and lessons on the properties
of water.
Winter, Mark. Webelements. Sheffield, England. February 1, 2005.
http://www.Webelements.com/webelements/scholar/index.html
This site provides an online periodic table, history of each element,
physical properties, electronic configuration, and the structure of each
element and their compounds. It also outlines the safety procedures when
handling the elements, and uses of these elements.
Wynn, Charles M. and Arthur W. Wiggins. The Five Big Ideas. New York: John
Wiley& Sons, Inc.,1997.
This book gives account of the major scientific discovery such as the plate
tectonics, tracing the elements roots, the model of an atom, and sorting out
elements. (The Periodic Table)
whatermelonman
> There are many sayings about teaching as a profession.
One way is to not overwhelm them, reward them, or listen to them
instead of this terrible effort at teaching.
See Ya,
sagetea
Connie
> Not trying to teach while you'r tweeking might help a bit
Nah, I can't believe that!
Uncle Al
>
> There are many sayings about teaching as a profession.
1) The teacher must be competent.
2) The students must be sufficently intelligent to benefit from
instruction.
3) Management must not be dedicated to putting lipstick on pigs.
http://www.diversity.umich.edu/programs/
The University of Michigan has more than 80 diversity programs.
But what about the Gifted?
http://www.giftedstudy.com/residential/michigan/index.asp
"The Summer Institute for the Gifted is not associated with the
University of Michigan. The SIG program is held on the University of
Michigan campus..."
Personnel, Human Resources, Human Factors Engineering.
Schoolmarm, teacher, educator, bilingual Human Factors Engineer.
The fancier the uniform the more pathetic the soldiers.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm
Larry Hammick
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
news:4AFEF4BB...@hate.spam.net...
> sanboz wrote:
>>
>> There are many sayings about teaching as a profession.
> [snip 760 lines of puke)
One of those sayings is, Those who can, do, and those who can't, teach.
Shit, sanboz, your prolix self-flattery just grosses me out.
Nice work, Al, by the way.
sanboz
"Larry Hammick" <larryh...@telus.net> wrote in message
news:fPMLm.52072$Db2.13318@edtnps83...
suck-up