40 terms

Chem Unit 1 Key Terms

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matter
anything that has mass and volume and exhibits inertia
mass
the amount of matter in an object
chromatography
separates the components of a mixture based on the differences in solubility and attraction to a surface
chemical change/reaction
a change that alters the composition of a substance
homogeneous mixture
uniform composition, properties and appearance throughout
alloy
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heterogeneous mixture
varying composition, properties and appearance throughout
physical change
The composition of a substance does not change. These can be classified as reversible or irreversible (irreversible changes may include changes in the size of matter).
chemical property
Observations of a substance that permanently change it into other substances; observations of its ability to react. Always intensive
physical property
observations of a substance that can be made without changing its composition
melting
(fusion) solid to liquid
condensation
gas to liquid
boiling
(vaporization, evaporation) liquid to gas
distillation
uses differences in boiling points; good for separating hetero or homogeneous mixtures, superior method to evaporation because all components can be isolated and retained (used to purify water)
phase
any part of a system that has uniform composition throughout
pure substance
matter with distinct properties and definite composition
solid
particles are tightly packed, and in a fixed pattern. Does not flow to fill container; definite shape and definite volume
liquid
particles slide past each other, definite volume no definite shape. Fills container, less dense
gas
particles very far apart. Constant, random motion. Least dense phase of matter. No definite shape or volume.
element
simplest form of matter; cannot be broken down into simpler substances by ordinary chemical means
chemical symbol
represents element in the periodic table- always one or two letters with the first letter capitalized
reactant
a substance that takes part in and undergoes change during a reaction
phase change
physical changes between solid, liquid, and gas
sublimation
solid to gas
filtration
uses differences in states of matter or particle size, and solubility; good for separating heterogeneous mixtures
atom
smallest unique particle that retains the identity of a substance
centrifuging
uses differences in density; and must be followed by filtration or decanting. usually used for separating heterogeneous mixtures
vapor
gaseous state of a substance that exists as a liquid or solid at room temperature
compound
can be separated into its components by chemical means. Atoms combine to form them, sometime called molecules. Have unique properties that are different than the elements that they contain
solution
homogeneous, chemicals mixed together
formula subscripts
represents the number of atoms of an element in a compound. The number is found to the lower right of the element's symbol
product
the species formed from chemical reactions. During a chemical reaction reactants are transformed into them after passing through a high energy transition state
vaporization
liquid to gas (evaporation, boiling)
decanting
also takes advantage of differences in density; a crude separation technique for heterogeneous mixtures
deposition
gas to solid
fusion
solid to liquid (melting)
signs of chemical change
color change, gas produced, temperature change (feel hot/cold), formation of a precipitate (liquid to solid), light
101.3 kPa, 1.00 atm, 760. mmHg, 760. torr
Standard atmospheric pressure
intensive
does not depend on amount of matter
extensive
depends on amount of matter