BJU Physical World - Intro to Physical Science - Ch 6
Question
Answer
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.
Science Vocab 147928
