PSU Freshman Chem 110 Final

atomic notation

top number=atomic mass=protons+neutrons, bottom number=atomic number=number of protons in nucleus=number of electrons

subatomic particle masses

protons and neutrons - 1amu, electrons have almost no mass

find number of neutrons

the number of protons is the same as the atomic number, and you know the mass number, solve out for neutrons

cations vs anions

cation gives away electrons, anion receives electrons, cations are metals, anions are nonmetals

isoelectronic

two atoms/ions with the same number of electrons

isotope

same number of protons and electrons, different number of neutrons. different mass numbers

find atomic mass from isotopes of a given element

∑(Mass of isotope * relative abundance)

internal energy

potential+kinetic

if change in energy is positive, energy is __ by the system and ___ by the surroundings, and vice versa

gained, lost

energy transfer in terms of heat and work

∆E=q+w

light can be studied as two things

waves and particles

speed of light value

3*10⁸ m/s

energy of a photon

∆E=hv | frequency * (6.626*10^-34 plank constant)

absorbs energy vs release energy photon

absorbs- higher energy level, endothermic | release- lower energy level, exothermic

ground vs excited states

ground is when the electron is at the lowest energy orbital. excited is when its higher

photon energy formula

∆E=Efinal-Einitial= RH (1/n²initial - 1/n²final) | RH= 2.18*10^-18

endothermic vs exothermic reaction products and reactants

endothermic the sign of H is positive and the products have more PE than the reactants. vice versa

in a frequency problem, negative exponent answers are usually __ and positive are usually __

wavelength, frequency

state function

quantity is independent of the path

electromagnetic spectrum, range of visible light

radio, micro, infrared, visible, ultraviolet, xray, gamma ray | 400-750

relationship between frequency and wavelength

inversely proportional

principal quantum number (n)

enegry level, distance from nucleus, higher the orbital higher the energy

angular momentum quantum number (l)

0 to n-1, describes shape

magnetic quantum number (Ml)

between -L and L | orientation in 3d space of orbital around nucleus

spin quantum number

+½ or -½ can't have 0

pauli exlcusion principle

no two electrons can have the same 4 quantum numbers, no more than two electrons can be in each orbital (CANT HAVE SAME SPIN)

angular momentum quantum number shapes

0=s=sphere, 1=p=dumbbell, 2=d=clover/dumbbell donut, 3=f=complicated

number of possible L values equals _ and the number of possible Ml values equals _

n, 2L+1

higher energy means its ___ to remove an electron

easier

what is easier to remove e⁻ from, s or p, and why

p, because of shielding, p can hold more electrons so more shielding occurs

effective neuclear charge

positive charge experienced by the negative electron that is reduced because of shielding

electron configuration

distribution of electrons within the orbitals

aufbau principle

electrons are placed in orbitals beginning with the lowest energy, low to high

hunds rule

fill degenerate orbital individually one at a time before pairing electrons

the electrons still visible in the noble gas configuration are

valence

transition metals electron configuration exception

elements in 6B and 1B borrow an electron from the s orbital to complete the d orbital

shells vs subshells

shell- collection of orbitals with same value of n | subshell- set of orbitals with same n and l values

how many orbitals in a subshell

2L+1

how many subshells per shell

n

number of orbitals in each shell

n²

half filled shells are _ stable

more

excited state

electron has been promoted to higher energy orbital (3p6 becomes 3p5 4s1)

atomic size and principal quantum number

as principal quantum number increases, the outer electrons are further from the nucleus and the atom is larger

atomic size and Zeff

as Zeff increases the outer electrons are pulled closer to the nucleus thus the atom is smaller

atomic size trend

increases right to left, and top to bottom (smallest is flourine)

ionic size

size of an atom when it either gains or loses its electrons

how to find ionic size

convert the ion to the element it is isoelectronic with, then to break ties use the trend

ionic size trend

increases right to left, and top to bottom

ionization energy

energy required to remove an electron from its orbital

ionization energy and principal quantum number

as principal quantum number increases the outer electrons are further from the nucleus and are easier to remove and therefore have lower ionization energies

ionization energy trend

increases bottom to top and left to right

Zeff trend

increases left to right and bottom to top

when there is a drastic change in ionization energy required to remove a successive electron, this indicates

the one that requires the jump is a core electron and not a valence

lattice energy

binding energy (energy required to break apart) between atoms in an ionic compound

lattice energy and charge, lattice energy and size

larger charge higher lattice, smaller size larger lattice

electronegativity

an atom's tendency to attract electrons

electronegativty trend

increases bottom to top and left to right

mass percent

total mass of the element in the compound / mass of one mole of the compound

how to find empirical formula

1. turn percent into grams 2. divide grams present by the molar mass of that element from the table 3. take the smallest number present from that calculations and divide every number by that one 4. if they dont work out to be whole numbers multiply by 2 for halves must by 3 for thirds

how to find molecular formula

divide molecular weight which is given by the empirical weight then multiply all the subscripts by that number

how to find empirical formula when given a molecular formula

divide out by the smallest subscript

how many orbital per subshell

s-1, p-3, d-5, f-7

electron fill pattern

1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5p,6s

why are valence involved in reactions but core are not

core are under high zeff, valence are shielded from it

3d vs 4s exception for atomic numbers greater than argon

3d doesn't get filled first 4s does

metals

lose electrons, good conducts

nonmetals

gain electrons, poor conductors

group 1

alkali metals

group 2

alkaline earth

group 6

chalcogens

group 7

halogens

group 8

noblegasses

ionic bonding

two ions of opposite charge (metals and nonmetals) trading electrons

covalent bonding

sharing not trading, between nonmetals or nonmetals and metaloids

polyatomic ion subscript names

1 is hypochlorate, 2 is chlorite, 3 is chlorate, 4 is perchlorate

polyatomic ions

.

ammonium

NH⁺

oxide

o²⁻

sulfide

S²⁻

hydroxide

OH⁻

acetate

CH₃COO⁻

sulfate

SO₄²⁻

sulfite

SO₃²⁻

carbonate

CO₃²⁻

phosphate

PO₄³⁻

hydrogen peroxide

h2o2

sulfuric acid

H2SO4

nitric acid

HNO₃

ammonia

NH₃

carbonic acid

H2CO3

acetic acid

CH3COOH

valence number is the same as _

group number

how to draw lewis structures

1. count the number of valence electrons

2. draw framework for the structure and connect each atom with single bonds - subtract two for every bond from the total valence

3. place remaining electrons into structure as lone pairs beginning with outer atoms first until you run out of electrons, make sure each atom has 8 including the two from the bond

4. consider adjustments to satisfy stability requirements- all atoms have octets, fewest formal charges possible, more e negative atoms have negative and least e negative atoms have positive

6. possible adjustments- move an electron pair from an atom with a negative charge to form a second bond to a neighboring atom that has a positive charge or incomplete octet | adjust the framework - go back to step two, could be necessary if you have charge centers that can't be minimized by forming double bonds

B and Be octet rule exception

have fewer than eight electrons so dont form a double bond

odd electron molecules octet rule exception

odd number of valence, not all electrons can pair up so one has a lone electron

overfilled octet octet rule exception

period 3 or higher dont need to obey octet, can be bonded to more than four atoms or have more than 8 electrons surrounding them

bond order

number of covalent bond

bond length

distance between two nuclei

bond dissociation energy

energy required to break covalent bond

bond order and bond length relationship

BO# increases, BL increases