Answer:
not significant to the overall mass of the atom
Explanation:
The mass number of an atom is the combination of the mass of the protons and neutrons. Electrons are not included because their mass are so insignificant that is doesn't change the total mass much, therefore they are left out. The mass of an electron is about 1,830 times smaller than protons and neutrons.
Answer:
C:ocean plates collide w/ the continetal plates
A2
B4
C1
D3
I think sorry if I get one wrong