| Term | Definition |
|
atomic mass |
number of protons and neutrons in the nucleus of an atom |
|
periodic table |
a chart that organizes information about all of the known elements according to their properties. |
|
atomic number of an element |
the number of protons contained in the nucleus of each of its atoms |
|
period |
each horizontal row in the periodic table - elements in each horizontal row increase in atomic number, moving across the row from left to right |
|
group |
a vertical column in the periodic table that is a chemical family |