| Question |
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| Answer |
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| alpha decay
|
A nuclear reaction in which an alpha particle is emitted. |
| alpha particles
|
A particle made up of 2 protons and 2 neutrons; a helium nucleus. |
| atomic mass |
The total of the masses of the particles in an atom. |
| atomic mass unit (amu) |
A unit used to measure the mass of an atom; 1/12 of the mass of a carbon-12 atom. |
| atomic number |
The number of protons in the nucleus of an atom. |
| beta decay |
A nuclear reaction in which a beta particle is emitted. |
| beta particles |
A free electron emitted from a nucleus in nuclear decay. |
| chain reaction |
A nuclear change that occurs when one unstable nucleus emits neutrons, which cause other nuclei to split and release neutrons, which hit other nuclei and continue the reaction, releasing a tremendous amount of energy. |
| electrons |
A negatively charged particle with an extremely small mass. |
| energy levels |
A region in an atom that contains electrons of a certain energy. |
| fission |
The splitting of a nucleus. |
| fusion |
The joining together of smaller nuclei into a larger one. |
| gamma rays |
A form of radiation consisting of high-energy electromagnetic waves; electromagnetic waves that originate in the nucleus of an atom; the type of electromagnetic waves with the highest frequencies. |
| isotopes |
Different forms of the same element that have different numbers of neutrons. |
| isotopic notation |
The special notation that an isotope is indicated by. |
| law of definite proportions |
A chemical compound is always made up of the same elements in the same proportions. |
| mass number |
The sum of the protons and neutrons in the nucleus of an atom; also known as atomic mass. |
| neutrons |
A neutral particle in the nucleus of an atom, with approximately the same mass as a proton. |
| nuclear bombardment reaction |
Occurs when the nucleus is struck with atomic particles or other nuclei. |
| nuclear chemistry |
The study of reactions involving atomic nuclei. |
| nucleus |
The center of an atom, which contains protons and neutrons. |
| orbitals |
Regions of most probable location of electrons. |
| planetary model |
Bohr's model of an atom; it looks like a miniature 3-D solar system. |
| protons |
A positively charged particle in the nucleus of an atom; 1836 times heavier than an electron. |
| quantum mode |
Represents the location of electrons as general and indefinite, with electrons being present in cloud-like orbitals. |
| radioactivity |
The emission of rays and particles from an unstable nucleus. |
| theory of relativity |
E=mc*2; an equation that establishes the relationship between loss of mass and loss of energy; that mass and energy are equivalent. |
Ch.18 LTI-MA 509
