chem GT - midterms

suspension

particles visible under an ordinary microscope

pure substance

made of one kind material with a unique set of chemical aND physical properties

pure element

can not be separated into simpler substances

compound

contains two or more elements chemically combined into a fixed ratio

mixture

blend of two or more pure substances that are not chemically combined

homogeneous mixture

does not contain visibly different parts, uniformly distributed, a solution

heterogeneous mixture

does contain visibly diff parts, not uniformly distributed

colloid

suspended particles that are larger than molecules but too small to drop out of suspension due to gravity

matter

mass & volume

solid

holds its shape, definite volume

liquid

flows freely, does not hold shape, definite volume

gas

no definite shape or volume

plasma

similar properties to gas/liquid, only exist at high temps

volume

amount of space something takes up

uncertainty

last digit written for a measurement is assumed to be your uncertain digit

physical change

takes place w/o changed in molecular composition; does not alter identity of substance

chemical change

alters the composition of original matter and identity

physical properties

observed w/o altering identity

chemical properties

cannot be observed unless altered the substance

quantitative property

properties that are measurable

qualitative property

properties you can sense (SUBJECTIVE)

density

ratio that describes how much volume and object or particular substance of a mass takes up (mass/volume), physical & quantitative property

evaporation

separate dissolved from liquid in solid liquid mixture (heating solution until solvent evaporates, leave behind solid residue)

decantation

separate solid from liquid in solid liquid mixture (carefully pour)

filtration

heterogeneous mixture composed from liquid solid of gas solid mixture (filter paper)

distillation

separate liquid from liquid liquid (difference in boiling point)|

metal

metallic luster, mostly solid at rm temp, malleable (can be hammered or pressed into diff shapes wo breaking), ductile (capable of being drawn into thin sheets or wire wo breaking), conducts heat and electricity

nonmetal

rarely has metallic luster, most are gasses, neither malleable or ductile, poor conductors of heat and electricity

semi metals

b, si, ge, as, sb, the, Po, at, look metallic but brittle, neither good conductors or insulators, semiconductors

radiation

energy that is released as particles or rays in a radioactive decay (like ALPHA PARTICLES) biggest type

oxidation number

potential gain or loss of sharing of electrons in chemical bond or reaction

noble gas configuration

atom consists of the elemental symbol of the last noble gas prior to that atoms In brackets followed by config of remaining electronsdc