Across
- 2. A subatomic particle of about the same mass as a proton but without an electric charge
- 5. The time required for a quantity to reduce to half of its initial value
- 8. His model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths
- 9. Any atom that bears one or more positive or negative electrical charges
- 12. Particle with negative electric charge
- 13. The most energetic form of electromagnetic radiation
- 14. Particle that has a positive electrical charge
Down
- 1. He discovered the electron in 1897 and proposed the plum pudding model of the atom in 1904
- 3. Center of an atom
- 4. To retain the part of incident radiated energy that is not reflected or transmitted
- 6. Identical to the nucleus of the helium-4 atom
- 7. The addition or removal of an electron to create an ion
- 9. Atoms with the same number of protons but different number of neutrons
- 10. High speed electron
- 11. The process by which an unstable atomic nucleus loses energy by radiation