Radioactivity comes from unstable atoms of certain elements. Radioactivity consists of alpha radiation (2 protons and 2 neutrons), beta radiation (1 electron), or gamma radiation (Electromagnetic photons).
If you move a substance from one container to another and its volume changes substances is gas.
Answer:
c 18.0ml
Explanation:
The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.