When different atoms join together, they are called a compound. Compounds are made of molecules (so molecules could be an alternate answer, but not all molecules are compounds)
H20 can be a molecule or a compound because it is made up of Hydrogen(H)
and oxygen (O)
They gain energy , it also allows plants to create organic molecules that they use as fuel.
The two angles would be both 41 degrees.

x in this case would be 14 degrees.
Density(D) is defined as Mass(M) divided by Volume(V).
The formula for Density is:
D = M / V.
Another way to remember the formula for Density is to remember "Mass per unit of volume".
I hope this helps!