Basics of Chemistry

scientific law

one proven statement, describing/predicting what happens in a specific situation

scientific theory

multiple thoughts that explain why something happens

modern chemistry

• change of one natural substance —→ another

• predict reactions

• understand atom/molecule interaction

Kinetic Molecular Theory of Matter

all matter made of atoms/molecules moving constantly and randomly

explains states of matter

solution

homogenous mixture of water & dissolved substances

mixture is uniform throughout

mixture

substance made of 2 or more components that are physically combined

elements

pure substance made up of one type of atom

cannot be broken down into simpler substances

chemical compound

2 or more elements connected with chemical bonds

original properties are replaced

molecules

smallest unit of a compound

extensive properties

depend on amount

(ex. mass, volume)

intensive properties

doesn’t depend on amount, used to identify materials

(ex. melting/boiling point, density)

physical properties

color, appearance, state, density, ductility (to be made into a wire), melting/boiling point, solubility (to be dissolved), electric conductivity, malleability (to be deformed under pressure), viscosity (resistence to flow)

physical change

identity is kept

change size, shape, physical state

same particles before and after

chemical change

1+ substances (reactants) —→ 1+ different substances (products)

represented using chemical equation

same # of atoms

chemical property

how easily materials chemically change in reaction with another material

kinetic energy

energy possessed due to motion

thermal, mechanical, electrical, acoustic energy

potiential energy

energy stored in a substance, because of its position/composition/arrangement

Law of the Conversation of Energy

neither created nor destroyed

total energy = constant

base unit of mass

kilogram (kg)

base unit of time

second (s)

base unit of temperature

Kelvin (K)

unit for amount of substance

Mole (mol)

base unit of electric current

ampere (A)

luminous intensity

Candela (cd)

giga

G

10^9

billion

mega

M

10^6

million