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Flashcards in chem chapter 6 test Deck (69)
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0
Q

what is electron affinity

A

a measure of the energy change when an electron is added to a neutral atom to form a negative ion

1
Q

what element is usually the central atom in lewis structure

A

whichever one is written first (except hydrogen will never be central)

2
Q

what is the electron affinity trend

A

increases down to up, left to right

3
Q

what is the atomic radii trend for cations?

anions?

A

cations: increases up to down, right to left
anions: increases up to down, left to right

4
Q

why does ionization energy increase left to right? down to up?

A

because atoms towards the right do not want to gain electrons, they want to lose
because the electrons are held in lower-energy orbitals, closer to the nucleus and therefore are more tightly bound (harder to remove).

5
Q

shared electrons=

A

N-A (always even)

6
Q

what is the difference between electron affinity and ionization energy

A

electron affinity is a measure of the energy change when an electron is added while ionization energy is the energy required to remove an electron

7
Q

what is electron affinity opposite of

A

ionization energy

8
Q

what is ionization energy

A

the energy required to move an electron from an atom is ionization energy

9
Q

why does fluorine have a higher ionization energy than iodine?

A

it has less electrons-lesser shielding/greater attraction between the electrons and the nucleus

10
Q

all atoms need 8 electrons, except…

A

hydrogen needs 2, boron needs 6, beryllium needs 4

11
Q

why does electronegativity increase down to up and left to right

A

This occurs due to a greater charge on the nucleus, causing the electron bonding pairs to be very attracted to atoms placed further right on the periodic table

12
Q

what is the electronegativity trend

A

increases down to up, left to right

13
Q

the differences in electronegativities is the classifier of bonds, what are the ranges for each

A

polar covalent 1.7>or equal to x > or equal to .5
pure covalent x<.5
ionic x>1.7

14
Q

what is the atomic radii trend

why

A

increases up to down(valence electron is occupying higher energy level/n value increases making radius larger), increases right to left (number of protons increases (nuclear charge) pulling the electrons in tighter making the radius smaller

15
Q

the larger the atom is, the (harder/easier) it is for electrons to be removed

A

easier

16
Q

ionization energy is always _____ meaning energy is added to the atom to remove the electron

A

endothermic

17
Q

H is never involved in a multiple bond

___,____ and ___ often form double and triple bonds

A

C, N, O

18
Q

total number of electrons should equal the ______ number

A

A

19
Q

isoelectronic means?

A

same number of electrons

20
Q

how are ionization energy and atomic radius related

A

inversely proportional

21
Q

what is the atomic radii

A

distance from the center of the nucleus to the “edge” of the electron cloud
usually measured in picometers or angstroms (1x10^-10m)
must be in gas form
center of nucleus to center of nucleus divided by 2

22
Q

what is shielding effect

A

inner electrons shield valence electrons from positive charge of the nucleus (protons) (concert analogy)

23
Q

______ do not have ionic radii because they do not form ions

A

noble gases

24
Q

when hydrogen becomes an ion, it is just an ____

A

electron

25
Q

number of bonds=

A

S/2

26
Q

why do elements in the same family generally have similar properties

A

they have the same amount of valence electrons

27
Q

what is electronegativity

A

holding onto its own electrons and taking other ones

28
Q

what is the metallic trend

A

increases up to down, right to left

29
Q

the number of available electrons is equal to the _____________

A

number of valence electrons of the atom

30
Q

what is the ionization energy trend

A

increases down to up, left to right

31
Q

why does electron affinity increase down to up, left to right

A

because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons

32
Q

covalent bonds are the _____ of electrons between two ________, one cation and one anion

A

sharing, nonmetals

33
Q

if a molecule has 4 total electron domains

what will it look like with 0,1,2,3 lone pairs on the central atom

A

tetrahedral, trigonal pyramidal, bent, —

34
Q

of hybrid orbitals formed= what

A

of domains on the central atom

35
Q

3 electron domains means _____ electron geometry and _____ bond angles

A

trigonal planar 120

36
Q

equal sharing in covalent bonds means ____

unequal sharing means _____

A

nonpolar (do not have opposite ends), polar

37
Q

if a molecule has 2 total electron domains

what will it look like with 0,1,2,3 lone pairs on the central atom

A

linear—-

38
Q

what is bond polarity determined by

A

electronegativity difference in the bond (dipole)

39
Q

double bonds only exist in ___

A

planes

40
Q

2 electron domains means _____ electron geometry and _____ bond angles

A

linear, 180

41
Q

how can you tell if a bond is polar

A

polar bonds have at least one of these two characteristics
one or more lone pairs on center atom (dipoles will angle)
if you have different atoms connected to your center (different electronegativities)

42
Q

4 electron domains means _____ electron geometry and _____ bond angles

A

tetrahedral, 109.5

43
Q

has a magnitude
has a value
has a direction
ex) velocity

A

vector

44
Q

if a molecule has 6 total electron domains

what will it look like with 0,1,2,3 lone pairs on the central atom

A

octahedral, square pyramidal, square planar, T-shaped

45
Q

6 electron domains means _____ electron geometry and _____ bond angles

A

octahedral 180/90

46
Q

if dipoles cancel, you have a ______ bond

how do dipoles cancel

A

nonpolar

same magnitude, towards or away from each other

47
Q

ionic bonds are a ____ of electrons between a ______ (which loses electrons and becomes a _____) and a _________ (which gains electrons and becomes a _______)

A

transfer, metal, cation, nonmetal, anion

48
Q

5 electron domains means _____ electron geometry and _____ bond angles

A

trigonal bipyramidal 180/120/90

49
Q

if a molecule has 5 total electron domains

what will it look like with 0,1,2,3 lone pairs on the central atom

A

trigonal bipyramdial, see-saw, T-shaped, linear

50
Q

how is molecule polarity determined

A

whether the dipoles cancel or if there is a resultant

51
Q

how do you indicate if a bond is ionic, polar, or nonpolar

A

ionic- >1.7
polar- .5-1.7
nonpolar- 0-.4

52
Q

if a molecule has 3 total electron domains

what will it look like with 0,1,2,3 lone pairs on the central atom

A

trigonal planar, bent, linear,–

53
Q

what is the dipole?

A

electronegativity inbalance, represented by arrows drawn towards more electronegative element
where electrons are found within the bond

54
Q

explain AXE notation

A

A-central atom
X- atoms bonded to central atom
E- lone pairs on central atom only
example) PF5’s notation would be AX5

55
Q

lone pairs on the central atom will result in a bond angle that is ____________ ideal

A

less than

56
Q

electrostatic attractive force between the partially positive charged hydrogen end of an O-H, N-H, or F-H bond and the negative charge of a lone pair on an O, F, or N

A

hydrogen bonding

57
Q

electrostatic attractive force between any two molecules

A

london dispersion force

58
Q

electrostatic attractive force between two polar molecules

A

dipole-dipole

59
Q

molecules with an indicated charge on in ____ with the charge drawn on the ___

A

brackets, outside

60
Q

what is the more polar of the following two bonds with the indicated electronegativity inbalance
B—>F (2.0)
B—>I (0.5)

A

B—>I because B—>F(2.0) is ionic

61
Q

choose the orbital in which an electron would experience the highest effective nuclear charge (least shielded) and the highest ionization energy
Na (3s) Mg (3s) Al (3p) P (3p) S (3p)

A

Mg (3s)

closest to the nucleus

62
Q

atoms are ____ stable alone than combined with other atoms

why

A

less

they have to use energy to combine therefore become more stable

63
Q

bond polarity refers to the equal (___) or unequal (___) sharing of electrons
molecular polarity refers to the symmetry(___) or asymmetry(___) of a molecule

A

nonpolar, polar, nonpolar, polar

64
Q

what makes a bond polar (covalent)

if the bond occurs between two ___ nonmetals

A

different

65
Q

what makes a molecule asymmetrical?

if there are ____________ around the central atom and/or if the surrounding atoms are different ______

A

lone pairs, elements

66
Q
smallest unit formula unit
exists as solids, usually crystal shapes
have high melting points
most dissolve in water
melted or dissolved in water conduct electricity
fixed + and - parts; anions and cations
examples KCL, NaF, KNO3
A

ionic compounds

67
Q

smallest unit molecule
exists as liquids, gases, or non-crystal solids
have low melting points
few dissolve in water
melted or dissolved in water does not conduct electricity
may have slightly + and - parts or totally neutral
examples NH3, CO2, CH4

A

covalent (molecular) compounds

68
Q

ionic compounds minimize PE by organizing into _____

A

crystals