If the atomic mass of an Atom is 18 how many neutrons are in the nucleus

Global warming was a major concern some people do not care global warming is fake it is not real the percentage of it happening  is slight 

What does the start look like

Answer it orbits high above earth to gain clearer images of light, it magnifies images relative to the human eye, it records most of the universe as it was in the past, not as it is now;

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