 | Term | Definition |
| |
science |
the study of nature |
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chemistry |
study of matter and its changes |
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The scientific method |
observation, question, hypothesis, experiment, conclusion |
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hypothesis |
one or more testable assumptions put forth in an attempt to answer a question |
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theory |
an attempt to explain why nature behaves the way it does... can change as technological advances occur |
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law |
a well tested and proven fact about nature.. a universal truth that doesn't change |
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qualitative observations |
observations that are observed (ex. color, shape) |
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quantitative observations |
observations that are calculated (ex. time, mass) |
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3 states of matter |
solid, liquid, gas |
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pure substance |
a substance with constant composition |
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element |
a substance that cannot be decomposed into simpler substances by chemical or physical means |
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compound |
a substance with constant composition that can be broken down into elements by chemical processes |
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matter |
has mass and takes up space (volume) |
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density |
describes how closely packed the particles of matter are (mass/volume) |
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homogeneous mixture |
a mixture that is the same throughout; a solution |
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heterogeneous mixture |
a mixture that has different properties in different regions of the mixture |
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solution |
a homogeneous mixture; the same throughout |
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filtration |
the method for seperating the components of a mixture containing a solid and a liquid |
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distillation |
a method for separating the components of a liquid mixture that depends on differences in the ease of vaporization of the components |
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ion |
an atom or a group of atoms that has a net positive or negative charge |
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isotope |
atoms of the same element (the same number of protons) that have different numbers of neutrons |
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mass number |
the total number of protons and neutronsin the atomic nucleusof an atom |
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atomic number |
the number of protons in the nucleus of an atom |
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diatomic elements |
H2, N2, O2, F2, Cl2, Br2, I2, At2 (not in subscript) |
| |
binary compound |
a two-element compound |
| |
ionic compound |
a compound that results when a metal reacts with a nonmetal to form cations and anions |
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polyatomic ions |
ions which contain two or more atoms covalently combined |
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molecular compounds |
two or more elements (nonmetals) covalently bonded |
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dimensional analysis |
a method of solving problems by studying and using the units of the meaurements in the problem |
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reduction |
atom gains electrons |
| |
oxidation |
atom loses electrons |
