1. Rutherford's gold foil experiment was instrumental in:

A. the discovery of the electron
B. the discovery that an atom is mostly empty space
C. the discovery of alpha particles
D. both "A" and "B"

2. Which of the following statements is NOT part of Dalton's atomic model?

A. each element has its own type of an atom
B. atoms can be broken down into sub- atomic particles
C. all matter is made of tiny particles called atoms
D. atoms of the same element are identical.

3. A cation is formed when

A. the atom loses electron/electrons
B. the number of neutrons is changed
C. the atom gains electron/electrons
D. the number of protons is changed

4. Isotypes are

A. atoms with the same number of protons and neutrons inside the nucleus
B. atoms with the same number of protons but different number of neutrons
C. atoms with different number of protons and electrons
D. atoms with the same number of neutrons but different number of electrons.​