Why can mass spectrometry be used to identify compounds?

What are the charges of the subatomic particles by choosing the answer from the drop down menu. protons have a (+1,0,or-1). (protons,neutrons,electrons) have a 0 charge. 3.) electrons have a (+1,0,-1)

Which statement describes both homogeneous mixtures and heterogeneous mixtures?

What material does not melt at any temperature