Honors Chemistry Unit 2 (Classifying Matter)

matter

substance and mixture

substance

elements and compounds

extensive properties

depend on amount

extensive properties examples

mass, volume, length

intensive properties

depends on the TYPE of matter (not amount)

intensive properties examples

density, melting point, boiling point

physical property

condition of a substance that can be observed without changing the substance

physical property examples

mass, volume, length, density, melting point, boiling point

chemical property

how one substance reacts with another

chemical property examples

CH4 (methane) reacts with O2

solis (s) or (cr)

fixed shape and fixed volume

liquid (l)

takes shape of container, fixed volume

gas (g)

takes shape and volume of container

elements

atoms of the same element always have the same number of protons, cannot be broken down by chemical reactions

compounds

combinations of atoms, can only be broken down by a chemical reaction

atomic number

number of protons an atom has

how to find the number of neutrons

mass = number of protons + number of neutrons

relationship between number of protons and neutrons in atoms

number of protons = number of neutrons

isotopes

same element with different number of neutrons

quantum mechanics

used for very small pieces of matter moving very quickly such as PHOTONS

newtonian mechanics

used for matter under usual conditions such as PROTONS

what are chemical reactions based on?

electrons

heisenberg uncertainty principle

it is impossible to know both the location and direction of an electron, the bohr model was dead

schroedinger’s equations

modern atomic theory; mathematical model that describes 90% probability orbitals, the best we can do is use probability to describe where electrons are likely to be found

aufbau principle

electrons occupy the lowest energy orbitals first

pauli exclusion principle

an atomic orbital can only hold two electrons each with a different spin

hund’s rule

with orbitals of the same energy, a single electron must occupy each orbital before they pair up

orbital

a pair of electrons

principal quantum number (n)

-tells you the energy level of the electron

-distance from the nucleus

-size of the electron cloud

second quantum number (l) —> (lowercase L)

-tells you the sublevels of the electron

sublevel s

can hold 2 electrons, shape is a sphere

sublevel p

can hold 6 electrons, shape is a dumbell

sublevel d

can hold 10 electrons, don’t worry about shape

sublevel f

can hold 14 electrons, don’t worry about shape

third quantum number (m)

-the space occupied by one pair of electrons is called an orbital

-describes the orientation in space of this orbital

fourth quantum number (spun quantum number) (s)

-no two electrons can live in the same space, in other words, occupy the same spot so this quantum, number designates the “spin” of the electron

valence electrons

electrons that are located in the outermost electron shell of an atom (highest energy level)

electron configuration chart

what determines the order of the elements on the periodic table?

the number of protons

what determines the shape of the periodic table?

electron configuration

s block

groups 1 and 2

p block

groups 13 through 18

d block

groups 3 through 12

f block

lanthanide series and actinide series

what do atoms become when they gain or lose electrons?

ions

noble gases

group 18

octet rule

to become stable, atoms want 8 electrons in their outer shell (hydrogen and helium want 2)

oxidation number (charges)

the most common charge that an element uas after it has

group 1 oxidation number

+1

group 2 oxidation number

+2

aluminum oxidation number

+3

zinc oxidation number

+2

silver oxidation number

+1

group 15 (N as P) oxidation number

-3

group 16 oxidation number

-2

group 17 oxidation number

-1

atomic radii (trend: increasing from top to bottom)

size of the atom

first ionization energy (trend: increasing from left to right, increasing from bottom to top)

amount of energy needed to pull the highest energy level electron off of the atom

cation (metals)

positive ion

anion (non-metals)

negative ion

group 1 name

alkali metals

group 2 name

alkaline earth metals

groups 3-12 name

transition metals

groups 17

halogens

group 18 name

noble gases

wavelength

the distance from one crest to another, usually measured in m, cm, nanometers

wavelength symbol

frequency

how many waves pass a point per second, measured in hertz

symbol for frequency

the speed of light

3.0 × 10^8

planck’s hypothesis- energy is quantized

energy is given off in little packets called quanta/quantum/PHOTON, energy of a wavelength was related to its frequency