the average mass of all the isotopes of an element.
a chart of the elements showing repeating pattern of their properties.
a horizontal row of elements in the periodic table.
elements in the same vertical column of the periodic table; also called a family.
a one or two letter representation of an element.
a gas like state of matter consisting of a mixture of free electrons and atoms that are stripped of their electrons.
the process in which two atomic nuclei combine to form a larger nucleus, forming a heavier element and releasing huge amounts of energy.