Chapter 4 Vocabulary The Periodic Table Alkali Metal

Chapter 4 Vocabulary The Periodic Table

Alkali Metal An element from Group 1 on the periodic table

Alkaline Earth Metal An element from Group 2 on the periodic table

Atomic Number The number of protons in the nucleus of an atom

Electron A subatomic particle that has a negative charge

Group A vertical column of elements in the periodic table

Halogen An element from Group 17 on the periodic table

Ion An atom or group of atoms that has lost or gained one or more electrons and has a negative or positive charge.

Isotope An atom that has the same number of protons as other atoms of the same element but has a different number of neutrons

Mass Number The sum of the numbers of protons and neutrons in the nucleus of an atom

Metal An element located on the left side of the periodic table that is shiny and conducts heat and electricity well

Neutron A subatomic particle found in an atom’s nucleus that has no charge

Noble Gas An element from Group 18 on the periodic table

Nonmetal An element on the right side of the periodic table that conducts heat and electricity poorly

Nucleus An atom’s central region made up of protons and neutrons

Orbital A region in an atom where electrons can be found

Period A horizontal row of elements in the periodic table

Proton A subatomic particle that has a positive charge and is found in the nucleus of an atom

Semi-conductor or Metalloid An element that conducts electric current better than an insulator, but not as well as a conductor; located where metals and nonmetals meet on the periodic table

Transition Metal An element from Groups 3 -12 on the periodic table

Valence Electron An electron found in the outermost shell of an atom that determines the atom’s chemical properties