chem ch1

accurate value

agrees w/ actual value

precise data

agrees w/ itself, aka multiple measurements close together

mass

a measurement of the resistance of an object to a change in its state of motion

volume

the art of space an object takes up

density

the art of matter per unit of space

temperature

measurement of the avg kinetic energy of particles in substance/object

theory

explanation of observations that’s well supported by experiments

law

observation that seems to be universally true

a theory _____ become a law

can’t

the scientific method

initial observations —> question —> hypothesis —> experiment —> observations — hypothesis —> theory (write out circle)

mixtures

substances that can be separated into diff components by physical processes

heterogenous mixtures

have diff compositions in diff places, can be separated by repeated divisions

homogenous mixtures

uniform composition throughout, can’t be separated by repeated divisions but instead more complicated physical changes

pure substances

can’t be separated by physical processes

compounds

can be separated into other compounds and/or elements by chemical reactions

elements

can’t be further separated by chemical reactions

accuracy is reduced by

systematic error/bias: error in the same direction

precision is reduced by

random error: equally likely in all directions