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physical 12
chapter 12
Question | Answer |
---|---|
element | material made of 1 atom |
proton | positively charged ion |
periodic table | chart of elements in order by atomic number |
atomic symbol | abbreviation for an atom or element |
atomic number | number of protons in an atom |
neutron | atom with no charge |
nucleon | proton or neutron |
atomic nucleus | positively charged center of every atom |
electron | negatively charged ion |
isotope | set of atoms with different numbers of neutrons |
atomic mass | mass of an elements atoms |
period | hoizontal row in periodic table |
group | famiyl of elements |
physical model | representation of an object on some convienant scale |
conceptualmodel | helps us predict how systems behave |
atomic spectrum | considered to be an elements "fingerprints" |
quantum hypotheis | idea that light energy is contained |
quantum | small packet of ligh energy |
shell | overlapping atomic orbitals of similar energy levels |
valence electron | electron located in outermostr occupied shell in an atom |
radioactivity | unstable atomic nuclei break down and emit radiation |
alpha particle | nucleus of helium atom |
beta particle | electron emitted during the decay of nuclei |
gamma ray | electromagnetic radiation emitted by radioactive atoms |
rad | quanity of radiant energy equal to 0.01 |
rem | unit measuring ability of radiation to harm living tissue |
strong nuclear force | force of interaction between all nucleons |
half life | time it takes half the atoms in an isotope to decay |
transmutation | conversion of an atomic nucleus of one element into an atomic nucleus of another element |
nuclear fission | splitting ofthe nucleus of a heavy atom |
chain reaction | products of one reaction event stimulate further reaction events |
nuclear fusion | combination of the nuclei of light atoms to form heavier nuclei |
thermonuclear fusion | nuclear fusion produced by hightemp |
basic research | research of how the natural world operates |
applied research | developing applications through basic research |
molecule | submicroscopic particle consisting of a group of atoms |
submicroscopic | atoms and molecules so small we cannot observe them with optical microscopes |
physical change | substance charges a physical property without transforming |
physical property | physical attribute of a substance |
chemical property | ability of a substance to undergo a change |
chemical bond | attraction that holds two atoms together |
chemical change | change in atoms being rerranged into one or more new substances |
chemical reaction | synonymous with chemical change |
elemental formula | notation that uses the atomic symbol to denote how atoms are bonded together |
compund | atoms of different elements are bonded to one another |
chemical formula | notation used to indicate the composition of a compund |