Which statement describes a chemical property of bromine?
(1) bromine is soluble in water.
(2) bromine has a reddish-brown color.
(3) bromine combines with aluminum to produce albr3.
(4) bromine changes from a liquid to a gas at 332 k and 1 atm.

(3) Bromine combines with aluminum to produce AlBr3, I wouldn't really call this a chemical property but more of a reaction, but the rest are all physical properties.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom