How many hydrogen atoms are there in one molecule of PH3?

On molecules of PH3, there has to be 3 atoms.

Explanation:

The Element Hydrogen (H) has 3 attoms.

The Element Phosphorus (P) has 1 atom.

These two created into the molecule PH3, would have to have only 3 attoms because they are asking how many hydrogens atoms are in the molecule PH3.    

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.