64
The mass number of an element is the sum of its
- A. electrons, neutrons and protons
- B. electrons and protons
- C. protons and neutrons
- D. orbital electrons
- E. valence electrons
65
The phenomenon observed when dust particles collide randomly in a beam of sunlight is known as?
- A. Tyndal effect
- B. diffusion
- C. osmosis
- D. brownian movement
- E. dialysis