Chemistry Vocab

periodic law

the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements

period

A horizontal row of elements in the periodic table

group

Vertical column in the periodic table

metal

A class of elements characterized by physical properties that include shininess, malleability, ductility, and conductivity.

Nonmetals

Elements that are poor conductors of heat and electric current

Metalloid

An element that has some characteristics of both metals and nonmetals

Akali Metals

Group 1A, excluding Hydrogen. Highly reactive.

akaline earth metals

Metals with two valance electrons, found in Group 2A

transition metals

Groups 3-12, 1-2 electrons in the outer energy level, less reactive than alsali-earth metals, shiny, good conductor of thermal energy and electrical current, high density

halogen

An element found in group 17 of the periodic table

noble gas

Elements in group 8A of the periodic table. Have no charge and are gases under normal conditions. (Helium, Neon, Argon, Krypton, Xenon, Radon)

Octet

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

atomic radius

one-half the distance between the nuclei of identical atoms that are bonded together

ionic radius

Distance from the center of an ion's nucleus to its outermost electron

Electronegativity

the ability of an atom to attract electrons when the atom is in a compound

ionization energy

The amount of energy required to remove an electron from an atom