States of Matter

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Periodic Table Noun

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[peer-ee-od-ik tay-bull]

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Periodic Table

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A chart arranging elements by increasing atomic number, with elements of similar properties placed in the same column.

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Example: This periodic table shows that elements can be solids, liquids, or gases at room temperature, indicated by the color of their chemical symbols.

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Period Noun

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[peer-ee-ud]

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Period

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A horizontal row of elements in the periodic table, across which properties change in a predictable pattern.

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Example: This diagram shows a horizontal row on the periodic table, called a period. It highlights Period 3, which includes elements from Sodium (Na) to Argon (Ar).

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Group Noun

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[groop]

Back

Group

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A vertical column of elements in the periodic table whose members share similar chemical properties and electron configurations.

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Example: This image shows columns of elements on the periodic table. In chemistry, each vertical column is called a 'group'.

Front

Periodic Law Noun

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[peer-ee-od-ik law]

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Periodic Law

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The principle that the chemical properties of elements are periodic functions of their atomic numbers, repeating predictably.

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Example: This diagram shows that as you move across or down the periodic table, the size of atoms changes in a predictable pattern, an example of Periodic Law.

Front

Atomic Number Noun

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[uh-tom-ik num-ber]

Back

Atomic Number

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The number of protons in an atom's nucleus, which uniquely identifies a chemical element and its properties.

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Example: This diagram of a Carbon atom shows six green protons in its nucleus. The number of protons, which is 6 here, defines the element's atomic number.

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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 participates in the formation of chemical bonds.

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Example: This diagram of an oxygen atom shows six electrons in its outermost shell. These outer electrons are called valence electrons and determine how atoms bond.

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Electron Dot Diagram Noun

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

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Electron Dot Diagram

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A model of an atom where each dot represents a valence electron, arranged around the element's chemical symbol.

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Example: This diagram shows the chemical symbol for Carbon (C) surrounded by four dots, which represent its four outermost valence electrons.

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Ionization Energy Noun

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[eye-on-ih-zay-shun en-er-jee]

Back

Ionization Energy

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The minimum amount of energy required to remove the most loosely bound electron from a neutral gaseous atom.

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Example: This diagram shows that ionization energy is the energy needed to remove an electron from a neutral atom, turning it into a positively charged ion.

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Metals Noun

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[met-uls]

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Metals

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A class of elements characterized by being good conductors of heat and electricity, and are typically malleable and ductile.

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Example: This image displays samples of different metallic elements, such as silver (Ag) and gold (Au), showing they are typically shiny solids at room temperature.

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Transition Metals Noun

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[tran-zish-un met-uls]

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Transition Metals

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The metallic elements located in Groups 3 through 12 of the periodic table, often forming colored compounds.

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Example: This image shows examples of transition metals like copper, gold, iron, and chromium, which are typically hard, shiny solids at room temperature.