The oxygen atom has 4 valence electrons. Valence electrons are the electrons found in the outermost shell of an atom. These are the electrons that participate in chemical reactions during bonding. Since 4 electrons make up 2 pairs, an oxygen atom is capable of making <em>2 covalent bonds</em>.
Changing the volume increases the area that the molecules collide with so the force is spread over a larger area.
Answer:
Relative atomic mass or atomic weight is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass constant. The atomic mass constant is defined as being 1/12 of the mass of a carbon-12 atom.
