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Flashcards in Test 4 Deck (64):
1

VSEPR stands for

Valence shell electron pair repulsion

2

When it comes to repulsion list the 3 pair groupings from most repulsive to least

(lone pair, lone pair) > (lone pair, bond pair) > (bond pair, bond pair)

3

2 electron groups

linear, 180

4

3 electron groups

trigonal planer, 120

5

3 electron groups - 1 lone pair

bent, <120

6

4 electron groups

tetrahetral, 109.5

7

4 electron groups - 1 lone pair

trigonal pyramidal, <109.5

8

4 electron groups - 2 lone pair

bent, <109.5

9

5 electron groups

trigonal bypyramidal, 90,120

10

5 electron groups - 1 lone pair

seesaw, <120

11

5 electron groups - 2 lone pair

t-shaped, <90

12

5 electron groups - 3 lone pair

linear, 180

13

6 electron groups

octahedral, 90

14

6 electron groups - 1 lone pair

square pyramidal, <90

15

6 electron groups - 2 lone pair

square planar

16

Trend in atomic radius

Increases from top right to bottom left

17

nonbonding atomic radius is the same as this

van der Waals radius

18

bonding atomic radius is the same as this

covalent radius

19

How is the atomic radius measured in metals and nonmetals

Metals- 1/2 the distance between two of the atoms next to each other in a crystal of metal
nonmetals- 1/2 the distance between two of the atoms bonded togeather

20

The atomic radius is determined by this

a set of average bonding radii

21

Which is larger atomic radius or van der Waals radius

Atomic radius < van der Waals radius

22

Atomic radius is found by doing this

adding each atomic radius of a molecule to find the molecules atomic radius

23

Formula for finding effective nuclear charge

effective nuclear charge = actual nuclear charge - charge screened by the other electrons

24

Which group of elements atomic radius stays relatively consistant

transition metals

25

What is the exception to the rule when removing electrons to form a cation

In transition metals you remove the greatest N value shell first, even if it is not the reverse order

26

Paramagnetic, what is it, and how does it react in a magnetic field

an atom or ion that contains unpaired electrons, attracted to an external magnetic field

27

diamagnetic, what is it, and how does it react in a magnetic field

an atom or ion that contains no unpaired electrons, repelled by an external magnetic field

28

Trends in cations, and anions

Cations are much smaller than their respective atom, and anions are much larger than their respective atom

29

What is ionization energy

energy required to remove an electron from an atom or ion in its gasous state

30

What is the sign of ionization energy and why

positive, because it always takes energy to remove an electron

31

Trend in ionization energy

Increases from bottom left to top right

32

Are there any exceptions to the ionization energy trend, and if so what are they

Yes, half filled shells have lower then expected ionization energy

33

Where do jumps in ionization energy occur

when removing electrons past a stable electron core

34

What is electron affinity

energy change associated with the gaining of an electron by the atom in the gaseus state

35

What is the sign of electron affinity and why

usually, but not always negative. because an atom or ion usually release energy when it gains and electron

36

trend in electron affinity

become more negative as you move from the left to right

37

Are there any exceptions to the electron affinity trend, and if so what is it

yes, half filled shells are lower then the trend, and almost half filled shells are higher then the trend

38

trend in metalic character

Increases from top right to bottom left

39

What is the best reason to discribe why chemical bonds form

because they lower the potential energy between the charged particals that compose atoms

40

Three types of bonds

Ionic, covalent, metallic

41

metal to nonmetal form

ionic

42

nonmetal to nonmetal

covalent

43

metal to metal

metallic

44

Born-haber cycle formula is used for these types of bonds

ionic

45

Born-Haber cycle formula is

dH_f = sub + IE + BE + EA + lat

46

Trends in lattice energy

as the ionic radii increase as we move down the column, the ions cannot get as close to eachother and therefore do not release as much energy when the lattice forms

47

This happens to lattice energies as atomic radii increase and decrease

as ionic radii increase lattice energy becomes less exothermic(less negative),
as ionic radii decrease lattice energy becomes more exothermic ( more negative)

48

T/F: Electrons are always equally shared

F, the more electronegative atom uneually shares the electrons

49

This type of bond is between pure covalent and ionic

polar covalent

50

trend in electronegativty

increases from bottom left to top right

51

covalent bonds are classified by an electronegativity difference of this range, and do this with their electrons

0 - .4 , equally share

52

polar covalent bonds are classified by and electronegativity difference of this range, and do this with their electrons

.4 - 2, unequally share

53

Ionic bonds are classigied by an electronegativity difference of this range, and do this with their electrons

2+ , transfer

54

(4) Steps for writing Lewis structure for molecular compounds

1. Write the correct skeletal structure for the molecule\
2. calculate the total number of electrons
3. distribute the electrons among the atoms, giving octets to as many atoms as possible
4. If any atoms lack octets, form double/triple bonds as necessary to give them octets

55

For polyatomic ions do this in your lewis structures

1. put it in brackets
2. add/subtract the proper amount of electrons for the given ionic charge

56

How to find the formal charge

formal charge = number of valence electrons originally for the atom - (total lone pair electrons + 1/2 bonded pair electrons)

57

Odd electron species include

free radicals, incomplete octets, expanded octets

58

Free radicals have this

and odd number of electrons and are generally unstable

59

Some atoms that form incomplete octets include

Boron {B}, Beryllium {Be}

60

Atoms that may form expanded octets

Atoms that are at N>=3 may have expanded octets

61

Bond energy formula

dH_rxn = sum(d)H_bonds broken + sum(d)H_bonds formed

62

The sign of broken bonds, and the sign of formed bonds

broken bonds are positive, and formed bonds are negative

63

Exothermic reactions occur when

weak bonds break and strong bonds form

64

Endothermic reactions occur when

weak bonds form and strong bonds break