Unit 5 Vocab: Nuclear Chemistry and Star Cycles

2. the process of combining nuclei to produce a nucleus of greater mass
6. a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light
8. a star with a mass about eight times (or more) of our sun
10. an isotope that has an unstable nucleus and undergoes radioactive decay
11. a small very dense star that is typically the size of a planet; one of the final steps in the life cycle of a low mass star
12. the penetrating rays and particles emitted by a radioactive source
13. an aging smaller star; an intermediate step in the life cycle of a low mass star
16. the conversion of an atom of one element to an atom of another element
17. a star with a low mass (like our sun)
18. the process by which nuclei emit particles and rays
19. an electron resulting from the breaking apart of neutrons in an atom

1. the time required for one-half of the nuclei of a radioisotope sample to decay to products
3. a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass; one of the final steps in the life cycle of a high mass star
4. the splitting of a nucleus into smaller fragments, accompanied by the release of neutrons and a large amount of energy
5. a positively charged particle emitted from certain radioactive nuclei; it consists of two protons and two neutrons and is identical to the nucleus of a helium atom
7. an aging giant star; an intermediate the life cycle of a high mass star
9. the location of stable nuclei on a neutron vs proton plot
14. a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter; an intermediate step in the life cycle of a low mass star
15. a high-energy photon emitted by a radioisotope