The answer would be Rutherford inferred the existence of a dense, positively charged nucleus.
The answer is A warm air rises cool air sinks
Electrons = protons
protons = atomic number
protons + neutrons = atomic mass
Therefore: a) protons + 7 = 15
protons= 15 -7
protons= 8
B) Remember proton = atomic number
so atomic number = 8
C)Now we know the atomic number so we can easily check on the periodic table what element has an atomic number of 8, which is Oxygen
I would say the head and heart because if you swim deep in the ocean you will feel pressure in your heart and head because the muscles in your body are closing in on them
hope i helped
