Do all atoms carry the same number of protons and neutrons? Why or why not?

No

Explanation:

The number of protons in each atom is also it's atomic number on the periodic table, meaning each pure element has a different number of protons. You can tell how many neutrons are in an atom by looking at the atomic mass, which is protons + neutrons = atomic mass.

You are given the protons in the atomic number so take that minus the atomic mass to get the number of neutrons.

Answer: No

Explanation: Some atoms don't 'need' neutrons The hydrogen atom does not have any neutrons. However, as # of protons increases, the number of neutrons increases as well. Naturally, 'positive charges repel', so it wouldn't be possible to have more than one proton in the nucleus.