Nuclear Physics

2. nuclei with small masses combined into one big nucleus and energy is released
3. the positively charged dense center of an atom
7. radioactive decay where alpha particles are emitted from the nucleus
8. model of an atom that shows electrons in circular orbits around the nucleus
9. the distance between 2 consecutive peaks or troughs of a wave.
12. radioactive decay where there's redistribution of energy in the nucleus without change in atom's mass or charg
13. is an apparatus to measure a spectrum.
14. A collection of waves with a range of frequencies.
16. a substance made up of two or more elements bonded together
18. number of decays per second in a radioactive substance
19. an element whose atoms have different numbers of neutrons than protons
20. neutrally charged

1. time required for half of the atoms to decay
4. negatively charged
5. particle one of three basic particles that make up an atom
6. materials that undergo radioactive decay and emit penetrating rays
8. radioactive decay where a neutron is changed into a proton in nucleus and beta particle and antineutrino are emitted
10. smallest particle of an element, and the basic unit of matter
11. the number of protons in an atom and its order on the Periodic Table
12. When an electron is in a state of lowest possible energy
15. positively charged
17. a nucleus is divided in two or more fragments, neutrons and energy are released