total mass of the protons and neutrons in an atom, measured in atomic mass units
A table that shows the elements, their atomic number, symbol, and average atomic mass; elements with similar chemical properties are grouped together.
The number of protons in the nucleus of an atom.
a horizontal row of elements in the periodic table
group or family
vertical column on the Periodic Table; tells the number of valence electrons for an element
the ability of a substance to go through a chemical change
not chemically reactive
a characteristic of a substance that can be observed
The ability of a substance to combine with and change into one or more new substances.
a characteristic that can be observed or measured without changing the identity of the substance