Which of the following statements are true about nuclear decays and radioactivity?
1. Gamma decay involves emission of a 4He nucleus A: True B: False
2. A neutrino is a particle with a negative charge and a very small mass A: True B: False
3. The mass of a radioactive nucleus before decay is greater than the total mass of the decay products A: True B: False
4. Alpha decay involves emission of a 4He nucleus A: True B: False
5. Beta decay involves emission of an electron A: True B: False