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Gabriel Litke

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Aug 2, 2024, 8:54:19 PM8/2/24

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Then we go over those terms, focusing on atomic number (equals # of protons) and how atomic mass is the average mass of protons and neutrons. At this point, there tends to be 10-15 minutes left in class and I pass out the periodic table and tell them that everything in the entire universe is on this piece of paper. Another phrase to pique their interest.

I would do a few more examples in class, but for this is enough for a blog. I would next talk about how you can read the periodic table like a book from left to right, top to bottom. I talk about how the atomic number and the atomic weight increase from left to right, top to bottom. Then we use the last 5 minutes or so on a no-stakes pop-quiz.

Then we go over the answers to end class. I tell the students that they will start every class with a periodic table quiz and that I guarantee they will be able to find any element from any clue by the end of the unit. And they do.

Alchemists in the Middle Ages first introduced symbols for elements, which influenced modern chemists' use of symbols for convenience. Jons Jacob Berzelius invented the current system of chemical symbols. Elements' symbols are derived from their names in Latin, English, or the scientists who discovered them. Henry Moseley's work with X-ray spectra showed that atomic number, not mass, determines an element's position in the periodic table. This led to restating the periodic law in terms of atomic number and the modern form of the periodic table.Read less

Well, fret not! My unit study on the periodic table of elements and basic chemistry should make teaching this critical subject matter much easier. I take it one step at a time, and I break everything down to its basic elements. I promise that your kids will get the most out of this lesson and the activities included. I am also going to provide some tips and ideas on how to make this lesson more hands-on.

When reading the periodic table of elements, the atomic number represents the number of protons and the number of electrons contained within the given element. The atomic mass is the combination of the number of protons and the number of neutrons in the nucleus. The mass of a proton or neutron is 1 atomic mass unit (amu).

An element is a pure substance that cannot be broken down into simpler different substances. An element may contain more than one of the same atom, as we see above. Elements are represented by their chemical symbol found on the periodic table. For instance, C for carbon or He for helium.

Compounds are pure substances that consist of atoms of different elements that are bound together chemically. Water is the most common example of a compound. Compounds are represented by their chemical formula. The chemical formula for water is H2O.

The periodic table is a chart of the chemical elements organized by atomic number, from hydrogen, the element with the lowest atomic number (1), to oganesson, the element with the highest atomic number (118). The atomic number of an element is the number of protons in the nucleus of an atom of that element. It is the number of protons that gives the element its identity, as no two elements have the same number of protons.

Groups are the vertical columns and tell us the number of valence electrons an atom has in the outer electron shell. For instance, the elements in Group 1 have 1 valence electron, and the elements in Group 18 have 8 valence electrons. The exception to this rule is helium in Group 18 which has 2 valence electrons.

Periods are the horizontal rows and tell us the number of electron shells in an atom. There are 7 periods with Period 1 having one electron shell and Period 7 having 7 electron shells. A tip to remember the difference between Groups and Periods is Sentences are read left to right and end in a Period.

Nonmetals are located on the right side of the periodic table, and most nonmetals are gases, including halogens and noble gases. Nonmetals have a dull luster, they are poor conductors of heat and electricity, they are brittle, and they are neither malleable nor ductile.

The periodic table is a tabular array of the chemical elements organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson. The atomic number of an element is the number of protons in the nucleus of an atom of that element. Hydrogen has 1 proton, and oganesson has 118.

The arrangement of the elements in the periodic table comes from the electronic configuration of the elements. Because of the Pauli exclusion principle, no more than two electrons can fill the same orbital. The first row of the periodic table consists of just two elements, hydrogen and helium. As atoms have more electrons, they have more orbits available to fill, and thus the rows contain more elements farther down in the table.

The periodic table has two rows at the bottom that are usually split out from the main body of the table. These rows contain elements in the lanthanoid and actinoid series, usually from 57 to 71 (lanthanum to lutetium) and 89 to 103 (actinium to lawrencium), respectively. There is no scientific reason for this. It is merely done to make the table more compact.

The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called blocks. Elements in the same group tend to show similar chemical characteristics.

Vertical, horizontal and diagonal trends characterize the periodic table. Metallic character increases going down a group and decreases from left to right across a period. Nonmetallic character increases going from the bottom left of the periodic table to the top right.

The first periodic table to become generally accepted was that of the Russian chemist Dmitri Mendeleev in 1869; he formulated the periodic law as a dependence of chemical properties on atomic mass. As not all elements were then known, there were gaps in his periodic table, and Mendeleev successfully used the periodic law to predict some properties of some of the missing elements. The periodic law was recognized as a fundamental discovery in the late 19th century. It was explained early in the 20th century, with the discovery of atomic numbers and associated pioneering work in quantum mechanics, both ideas serving to illuminate the internal structure of the atom. A recognisably modern form of the table was reached in 1945 with Glenn T. Seaborg's discovery that the actinides were in fact f-block rather than d-block elements. The periodic table and law are now a central and indispensable part of modern chemistry.

The periodic table continues to evolve with the progress of science. In nature, only elements up to atomic number 94 exist;[a] to go further, it was necessary to synthesise new elements in the laboratory. By 2010, the first 118 elements were known, thereby completing the first seven rows of the table;[1] however, chemical characterization is still needed for the heaviest elements to confirm that their properties match their positions. New discoveries will extend the table beyond these seven rows, though it is not yet known how many more elements are possible; moreover, theoretical calculations suggest that this unknown region will not follow the patterns of the known part of the table. Some scientific discussion also continues regarding whether some elements are correctly positioned in today's table. Many alternative representations of the periodic law exist, and there is some discussion as to whether there is an optimal form of the periodic table.

Each chemical element has a unique atomic number (Z) representing the number of protons in its nucleus.[4] All elements have multiple isotopes, variants with the same number of protons but different numbers of neutrons. For example, carbon has three naturally occurring isotopes: all of its atoms have six protons and most have six neutrons as well, but about one per cent have seven neutrons, and a very small fraction have eight neutrons. Isotopes are never separated in the periodic table; they are always grouped together under a single element. When atomic mass is shown, it is usually the weighted average of naturally occurring isotopes; but if no isotopes occur naturally in significant quantities, the mass of the most stable isotope usually appears, often in parentheses.[5]

In the standard periodic table, the elements are listed in order of increasing atomic number Z. A new row (period) is started when a new electron shell has its first electron. Columns (groups) are determined by the electron configuration of the atom; elements with the same number of electrons in a particular subshell fall into the same columns (e.g. oxygen, sulfur, and selenium are in the same column because they all have four electrons in the outermost p-subshell). Elements with similar chemical properties generally fall into the same group in the periodic table, although in the f-block, and to some respect in the d-block, the elements in the same period tend to have similar properties, as well. Thus, it is relatively easy to predict the chemical properties of an element if one knows the properties of the elements around it.[6]

For reasons of space,[17][18] the periodic table is commonly presented with the f-block elements cut out and positioned as a distinct part below the main body.[19][17][10] This reduces the number of element columns from 32 to 18.[17]