Bonding and the Periodic Table

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Valence Electron Noun

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[vay-lence i-lek-tron]

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Valence Electron

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An electron in the outermost energy level of an atom that is involved in the formation of chemical bonds.

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Example: This Bohr model of a Sodium atom shows electrons in shells. The single electron in the outermost shell is the valence electron.

Front

Octet Rule Noun

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[ok-tet rool]

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Octet Rule

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The principle that atoms are most stable when their highest energy level is full, typically with eight valence electrons.

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Example: An oxygen atom with six outer electrons bonds with two hydrogen atoms to achieve a stable outer shell of eight electrons (a complete octet).

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Noble Gas Configuration Noun

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[noh-buhl gas kon-fig-yuh-rey-shuhn]

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Noble Gas Configuration

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A stable state where an atom's outermost energy level is full, identical to the electron structure of a noble gas.

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Example: This diagram shows an atom with a full outer electron shell. This stable arrangement, with eight electrons, is called a noble gas configuration.

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Group Noun

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[groop]

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Group

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A vertical column of elements in the periodic table, where elements share the same number of valence electrons.

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Example: This image shows a group of sodium (Na+) and chlorine (Cl-) ions arranged in an orderly, repeating pattern to form a crystal of salt.

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Period Noun

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[peer-ee-uhd]

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Period

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A horizontal row of elements in the periodic table, indicating the number of energy levels an atom's electrons occupy.

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Example: This image shows that a period is a horizontal row on the periodic table by highlighting all the elements in Period 3.

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Electron-Dot Diagram Noun

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[i-lek-tron dot dahy-uh-gram]

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Electron-Dot Diagram

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A model that uses dots around an element's symbol to represent its valence electrons and predict potential chemical bonds.

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Example: This diagram shows the symbol for carbon (C) with four dots, representing its four valence electrons, which are the outermost electrons in an atom.

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Metals Noun

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[met-ls]

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Metals

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A category of elements, found on the left side of the periodic table, that tend to lose valence electrons.

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Example: This image shows samples of common metals like copper, gold, and silver, which are elements known for their characteristic shiny luster.

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Nonmetals Noun

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[non-met-ls]

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Nonmetals

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A category of elements, found on the right side of the periodic table, that tend to gain or share electrons.

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Example: This image defines nonmetals by listing their key properties, such as being dull and poor conductors, and shows sulfur as a common example.

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Metalloids Noun

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[met-uh-loidz]

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Metalloids

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Elements located along the 'stair-step' line of the periodic table that have properties of both metals and nonmetals.

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Example: This image shows the location of the metalloids, such as Boron and Silicon, which form a stair-step line on the periodic table between metals and nonmetals.

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Reactivity Noun

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[ree-ak-tiv-i-tee]

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Reactivity

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The measure of how readily a substance undergoes a chemical reaction to achieve a stable, full outer electron shell.

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Example: The iron in these nails has high reactivity, causing it to chemically react with oxygen in the air to form rust.