Chapter 4 Vocabulary Terms

Periodic Law

The law that states that the repeating physical and chemical properties of elements change periodically with their atomic number.

Valence Electron

An electron that is found in the outermost shell of an atom and that determines the atom’s chemical properties.

Group

A vertical column of elements in the periodic table: element in a group share chemical properties

Period

A horizontal row of elements in the periodic table.

Main-group elements

An element in the s-block or p-block of the periodic table.

Alkali metal

Group 1 of the periodic table.

Alkaline Earth metals

Group 2 of the periodic table

Halogen

Group 17 of the periodic table

Nobel gas

group 18 of the periodic table

Transition metal

3-12 of the periodic table can use the inner shell before using the outer shell to bond.

Lanthanide

Member of the rare-earth series of elements, whose atomic numbers range from 58 to 71.

Actinide

Atomic numbers from 89 through 105

Ionization Energy

Remove 1 electron from an atom or ion.

Electron Shielding

The reduction of the attractive force between a positively charged nucleus and its outermost electrons due to negative charges cancelling inner electrons.

Bond Radius

Half the distance from the center to center of two like atoms that are bonded together.

Electronegativity

Ability of an atom in a chemical compound to attract electrons.

Nuclear reaction

Reaction that affects the nucleus of an atom.

Superheavy element

An element whose atomic number is greater than 106.