general chemistry (1-3 may 18th)

Question 1

atomic mass vs atomic weight

Answer 1

atomic mass is nearly synonomous with the mass number - sum of protons and neutrons

atomic weight is the weighted average of the atomic masses

Question 2

plancks and Bohrs energy calculations

Answer 2

E=hc/lamda = RH (1/ni2 - 1/nf2)

Question 3

Heisenberg uncertainity principle

Answer 3

it is impossible to determine with perfect accuracy the momentum and position of an electron, because of trying to do the two measurements at the same time

Question 4

maximum number of electrons within a shell

Answer 4

2n^2

Question 5

l quantum number

Answer 5

Angular momentum, describes the shape and number of subshells at the given energy level

l=0 is s
l=1 is p
l=2 is d
l=3 is f

Question 6

magnetic quantum number

Answer 6

tells u the specific orbital within a subshell that the electron is

possible values are integers -l to l, including zero

ex:
2p
l= 1
so -1, 0, 1 —> px, py,pz

Question 7

spin quantum number

Answer 7

ms, +1/2 or -1/2

Question 8

configuration for anions

Answer 8

just fill up orbitals in configuration

Question 9

configuration for cations

Answer 9

make to remove electrons from the highest n first,

ex: Fe 3+, remove electrons from 4s before 4d

Question 10

hunds rule

Answer 10

-subshells filled to have the max number of half-filled electrons with parallel spins
-half filled and fully-filled orbitals have higher stability than other states

Question 11

chromium configuration

Answer 11

special bc you move one out of s to have more half filled orbitals
[Ar]4s13d5

Question 12

paramagnetic

Answer 12

if they have ANY unpaired electrons, they are attracted to a magnetic field

Question 13

diamagnetic

Answer 13

only paired electrons, will be slightly repelled by a magnetic field

Question 14

valence electrons for transition elements

Answer 14

those in the highest s and d subshell

Question 15

valence electrons for lathinide and actinine

Answer 15

those in highest s and f subshells

Question 16

metals characteristics

Answer 16

lustrous, high melting points, malleability, ductility, high electropositivity

Question 17

transition metals

Answer 17

-electrons can move around- good conductors because of loose hold on electrons of the d orbitals
-forms hydration complex with water and nonmetals,

Question 18

nonmetals

Answer 18

dull, poor conductors, brittle

Question 19

metalloids

Answer 19

characteristics of both metals and nonmetals, staircase

Question 20

Zeff

Answer 20

effective nuclear charge, net positive charge experienced by electrons in the valence shell
-INCREASES LEFT TO RIGHT (more protons), little change in a group HOWEVER, valence electrons become increasingly separated as u move down a group

Question 21

atomic radius

Answer 21

Decreases left to right and up (think fluorine is small)

Question 22

Ionic radius (which is smaller and bigger?)

Answer 22

• cations smaller, anions larger

Question 23

key examples for exceptions to the octet rule

Answer 23

incomplete: boron: 2
expanded: phosphorus (10), sulfur (12), chlorine (14) - bc of d orbitals

Question 24

lewis acid

Answer 24

any compound that will accept a lone pair of electrons

Question 25

lewis base

Answer 25

Any compound that will donate a pair of electrons to form a covalent bond

Question 26

formal charge equation

Answer 26

=valence electrons- nonbonding - (1/2)(#of bonds)

Question 27

guidlines for the stability of resonance structures

Answer 27

-small or no formal charge preffered
-LESS charge separation between OPPOSITE charges
-negative formal charges on more electronegative atoms

Question 28

electronic geometries (simplified)

Answer 28

XY2 — linear
XY3 —- trigonal planar
XY4 —- teterahedral
XY5 —trigonal bipyramidal
XY6 —-octahedral

Question 29

polarity of molecules and vseper

Answer 29

even if the bonds are polar, if it’s symmetrical , the dipoles cancel and the molecule is nonpolar

Question 30

London dispersion forces

Answer 30

unequal electron density distribution - polarization and then depolarization, weakest, works best with large molecules

Question 31

hydrogen bonds what atoms

Answer 31

pick up the FON
fluorine, nitrogen, oxygen

Question 32

physical characterstics of ionic compounds

Answer 32

tends to dissociate in water
-conductivity, electrolytes
-crystal lattices

Question 33

coordinate covalent bonds

Answer 33

occurs when a single atom provides both bonding electrons, the other contributes none, think NH4+, one of the bonds is coordinate covalent