chem!

K

C + 273.15

1mL

= 1cm³

1Hz

= 1/s or 1s^-1

1J

= 1kg m²/s²

avogrado’s number

6.022 × 10²³/mol

speed of light in vacuum

3.000 × 10^8m/s

density

d = m/v

kinetic energy

KE = 1/2mv², photon energy - binding energy

frequency and wavelength

v=frequency, c=speed of light, ^=wave length

energy of a photon

de broglie relation

M

10^6

k

10³

d

10^-1

c

10^-2

m

10^-3

u

10^-6

n

10^-9

p

10^-12

precision

closeness of all values to each other

accuracy

closeness to actual value or target

multiplying or dividing sig figs

result is same number of sig figs as number with least amount of sig figs

adding or subtracting sig figs

results has same number of decimal places as number with least amount of decimal places

intensive properties

dont change with the amount of a substance

density, temp, color

extensive properties

changes with the amount of a substance, number measures the substance

mass, volume, energy

energy

capacity to do work

work

action of a force applied across a distance

w = F(d)

endothermic reaction

heat enters system, energy of system increases, temp in surrounding decreases

exothermic reaction

heat exits system, energy of system decreases, temp in surrounding increases

pure substances

elements or compunds

element

on periodic table, cannot be separated by chemical means

compund

combination of elements with fixed proportions, can be separated by chemical means

homogenous mixture

uniform, solute fully dissolve, can be separted by physical means

heterogenous mixture

not uniform, solute not fully dissolved, can be separated by physical means

law vs theory

law: summarizes past observations and predicts future ones

theory: model that explains why nature is the way it is

atomic theory

created by john dalton

1. each element composed of atoms

2. all atoms of given element have same mass and characteristics (we now know about isotopes)

3. atoms combine into simple, whole number ratios

4. atoms in one element cannot change into atoms of another element (we now know about fission and fusion)

electric field

a region where an electrically charged particle experiences a force

magnetic field

a region where a magnetized particle experiences a force

amplitude

amount of photons, measure of light intensity

wavelength

determines color

longest: red, low energy, low frequency

shortest: violet, high energy, high frequency

photon energy (E)

proportional to frequency, can only be positive

E = hv, E = hc/lambda

constructive interference

waves line up in phase when they meet and create a larger wave, makes light brighter

destructive interference

waves are out of phase when they meet and cancel each other out, makes it dark

diffraction

behavior that only happens with waves, not particles

threshold frequency

minimum frequency needed before electrons are emitted

binding energy

energy required to remove electron from metal

atomic spectra

unique patterns of light emitted or absorbed by atoms as their electrons move between energy levels

bohr model

electrons orbit nucleus in quantized energy levels, electrons can move between these levels by emitting or absorbing photons

n

number of orbitals

5d n=5

3s n=3

L

shape of orbital

0=s, 1=p, 2=d, 3=f

always less than n

m

orientation of orbital

-L to L

ms

electron spin

spin up = +1/2

spin down =-1/2

node

where probability density drops to 0

nodes = L

the more nodes the higher the energy

solution dilution

m1v1=m2v2

heat capacity

bomb calorimeter

enthalpy from bond energies

standard enthalpy

ideal gas law

dalton’s law

mole fraction

pressure

collisions with the walls

temperature

how fast gas particles are moving

dalton’s law

total pressure equals sum of each gas

mole fraction

what percent of the mixture is this gas

gas collected over water

gas pressure= total-water vapor

graham’s law

lighter gas is faster

ideal gasses

no volume and no attractions

high pressure, low temp= less ideal

hess’s law

if reactions add, their heat change values also add

if you flip reactions, you have to flip sign

lattice energy

stronger attraction when charges are bigger and when ions are smaller

stronger attraction=more energy

diffusion

mixing of gasses from areas of high to low concentration

effusion

escape of gas particle through a tiny hole into a vacuum or lower concentration area

combined gas law