Question

The lightest known element with only one proton is

Answer 1

That would be hydrogen!

Answer 2

The atomic number is the number of protons the element has. One proton, atomic number is one. Look up element number one on the periodic table and see what you find...

Answer 3

Please ask additional questions in additional threads - not all bunched together in one thread, thanks. :D

Answer 4

A negatively charged particle that orbits the center of an atom is called an

Answer 5

electron