What are the parts of an atom

1 electrons neutrons and protons?

2electrons and protons electrons protons neutron?

3 electrons protons neutrons and a nucleus

answer the questions above

Number three

They contain protons (positive), neutrons (negative), electrons (neutral) and all are in a nucleus which is part of an atom

It's number 2 I think. electrons, protons and neutrons. protons and neutrons in nucleus electrons outside. exception being "normal" hydrogen. one proton and one electron with no neutrons.

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.

The answer is: c. from underground