All compounds are molecules because a molecule is 2 or more substances/elements combined and a compound is 2 or more elements combined. But not all molecules are elements because some molecules are just combined substances with no elements combined at all.
Answer:
E = 147000 J
Explanation:
Given that,
The mass of meteor, m = 50 kg
The altitude of the meteor, h = 300 m
We need to find the potential energy of the meteor. The formula for the potential energy is given by :

Put all the values,

So, the required potential energy is equal to 147000 J.
When Lead (II) acetate and Hydrogen sulfide react, they form Lead sulfide and Acetic acid. The reaction is a reduction-oxidation (redox) reaction.
The balanced chemical reaction is this:
Pb(C2H3O2)2 + H2S --> PbS + 2C2H4O2
And the net ionic reaction is this:
Pb2+ + S2- --> PbS
Ca is the only element perhaps B