Potassium
K
The atomic number is 19 and the mass number is 39.0983. It is in period 1 and is in group 1 the Alkali Earth Metals. It is a solid, and it is a metal.
Pills
Potassium is used is some medicines.
Fireworks
Potassium is used to make so colors of fireworks.
Metals
Potassium is also used in some forms of metals.