horizontal rows on the periodic table
periods
vertical columns on the periodic table
families
negative subatomic particle
electron
number of protons in an element
atomic number
the electrons in the outermost energy level
valence
number of protons and neutrons
mass number
represents an element
symbol
neutral subatomic particle
neutron
positive subatomic particle
proton
Most of the elements in the periodic table
metals
The elements that are in between the zigzag line on the periodic table.
metalloids or semi-metals
The elements that are on the far upper right corner of the periodic table.
nonmetals
Elements in the first group on the periodic table with one valence electron and are very reactive.
Alkali Metals
Elements in the second group on the periodic table with 2 valence electrons and are very reactive.
Alkaline Earth Metals
Elements in group 3-12 that have many useful properties.
Transition Metals
Elements in group 17, known as “salt formers”
Halogens
Elements in group 18, very unreactive. They are said to be “inert”.
Noble gases
The elements in the first period at the bottom of the periodic table.
Lanthanide Series
The elements in the second period at the bottom of the periodic table.
Actinide Series
Being unreactive with other elements
inert
