science voc #2

periodic law

states that when the elements are arranged by increasing atomic number, there is a periodic repetition of their properties.

groups

a vertical column of elements in the periodic table arranged in order of increasing atomic number; also called a family.

periods

a horizontal row of elements in the modern periodic table.

representative elements

elements from groups 1, 2, and 13-18 in the modern periodic table, possessing a wide range of chemical and physical properties.

transition metals

elements in groups 3-12 of the modern periodic table and are further divided into transition metals and inner transition metals.

ion

an atom or bonded group of atoms with a positive or negative charge.

ionization energy

the energy that is required to remove an electron from a gaseous atom; generally increases in moving left-to-right across a period and decreases in moving down a group.

octet rule

states that atoms lose, gain, or share electrons in order to acquire the stable electron configuration of noble gas.

electronegativity

indicates the relative ability of an element’s atoms to attract electrons in a chemical bond.