Who proposed the planetary model of the atom?

What is the charge of an electron?

Which particle is found in the nucleus of an atom?

What is the atomic number of an element?

Which experiment proved the existence of the nucleus?

Which particle determines the chemical identity of an atom?

Which subatomic particle has nearly no mass?

What is the maximum number of electrons in the second energy level?

Which scientist discovered the electron?

The sum of protons and neutrons in an atom is called?