Water flowing through a small creek into a stream after a storm is an example of

Is there any opitions? if you have the periodic table, the noble gases are 8a family, the halogen are the 7a family, and the nonmetal are  carbon, nitrogen, phosphorus, oxygen, sulfur, selenium, fluorine, chlorine, bromine, iodine and astatine.

The density of the block of iron is lees than the density of mercury but the density of the block of iron is greater than the density of water

Cvelocity of the