Answer:
B) it reacts with sodium metal to form sodium hydroxide and hydrogen gas
Explanation:
B is the only option that show a chemical property, density, freezing, and boiling points are physical properties.
Answer: precipitate
Explanation: Chemical change is a change in which the chemical composition of the atoms changes. The following changes are seen when chemical reaction takes place:
1) Release or absorption of heat
2) Formation of solid or a precipitate

3) Change in color
4) Production of gas
He atom<span> consists of a tiny </span>nucleus<span> surrounded by moving electrons. </span>
It is based on Relative DENSITY.............
I think so. You should check the Periodic Table. ;-)