Hey there!:
Mass = 21.09 g
Volume = 6.44 mL
Therefore;
Density = mass / Volume
Density = 21.09 / 6.44
Density = 3.274 g/mL
The subatomic particle that identifies the atom is the number of protons. This is what distinguishes an element that is is flammmable, hydrogen to one that is essential component in water, oxygen.
