Answer:
True........................
In simpler terms, a proton and neutron weigh 1 amu (atomic mass unit) each.
The nucleus has 15 protons and 18 neutrons. Since a proton's and a neutron's weight is only 1 amu, we can simply add the number of protons and neutrons to find the total mass of the nucleus:

The nucleus' mass is 33 amu.
7) 6, i believe, (Cu) 1 atom+ (S) 1 atom+(0)4 atoms.
I can't see the answers clearly, but I can see the question. So, I'll just give you a clue/hint.
A stars brightness actually depends on how far it is from your location. If it's far away, it will be dimmer than its counterpart that is closer. To summarize it, if two stars have the same brightness level and one is farther away than the other, the one farther away will appear dimmer than its closer counterpart.