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

what element is usually the central atom in lewis structure

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

1

what is electron affinity

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

2

what is the electron affinity trend

increases down to up, left to right

3

what is the atomic radii trend for cations?
anions?

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

4

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

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

shared electrons=

N-A (always even)

6

what is the difference between electron affinity and ionization energy

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

what is electron affinity opposite of

ionization energy

8

what is ionization energy

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

9

why does fluorine have a higher ionization energy than iodine?

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

10

all atoms need 8 electrons, except...

hydrogen needs 2, boron needs 6, beryllium needs 4

11

why does electronegativity increase down to up and left to right

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

what is the electronegativity trend

increases down to up, left to right

13

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

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

14

what is the atomic radii trend
why

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

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

easier

16

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

endothermic

17

H is never involved in a multiple bond
___,____ and ___ often form double and triple bonds

C, N, O

18

total number of electrons should equal the ______ number

A

19

isoelectronic means?

same number of electrons

20

how are ionization energy and atomic radius related

inversely proportional

21

what is the atomic radii

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

what is shielding effect

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

23

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

noble gases

24

when hydrogen becomes an ion, it is just an ____

electron

25

number of bonds=

S/2

26

why do elements in the same family generally have similar properties

they have the same amount of valence electrons

27

what is electronegativity

holding onto its own electrons and taking other ones

28

what is the metallic trend

increases up to down, right to left

29

the number of available electrons is equal to the _____________

number of valence electrons of the atom

30

what is the ionization energy trend

increases down to up, left to right

31

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

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

32

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

sharing, nonmetals

33

if a molecule has 4 total electron domains
what will it look like with 0,1,2,3 lone pairs on the central atom

tetrahedral, trigonal pyramidal, bent, ---

34

# of hybrid orbitals formed= what

# of domains on the central atom

35

3 electron domains means _____ electron geometry and _____ bond angles

trigonal planar 120

36

equal sharing in covalent bonds means ____
unequal sharing means _____

nonpolar (do not have opposite ends), polar

37

if a molecule has 2 total electron domains
what will it look like with 0,1,2,3 lone pairs on the central atom

linear----

38

what is bond polarity determined by

electronegativity difference in the bond (dipole)

39

double bonds only exist in ___

planes

40

2 electron domains means _____ electron geometry and _____ bond angles

linear, 180

41

how can you tell if a bond is polar

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

4 electron domains means _____ electron geometry and _____ bond angles

tetrahedral, 109.5

43

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

vector

44

if a molecule has 6 total electron domains
what will it look like with 0,1,2,3 lone pairs on the central atom

octahedral, square pyramidal, square planar, T-shaped

45

6 electron domains means _____ electron geometry and _____ bond angles

octahedral 180/90

46

if dipoles cancel, you have a ______ bond
how do dipoles cancel

nonpolar
same magnitude, towards or away from each other

47

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

transfer, metal, cation, nonmetal, anion

48

5 electron domains means _____ electron geometry and _____ bond angles

trigonal bipyramidal 180/120/90

49

if a molecule has 5 total electron domains
what will it look like with 0,1,2,3 lone pairs on the central atom

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

50

how is molecule polarity determined

whether the dipoles cancel or if there is a resultant

51

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

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

52

if a molecule has 3 total electron domains
what will it look like with 0,1,2,3 lone pairs on the central atom

trigonal planar, bent, linear,--

53

what is the dipole?

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

54

explain AXE notation

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

55

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

less than

56

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

hydrogen bonding

57

electrostatic attractive force between any two molecules

london dispersion force

58

electrostatic attractive force between two polar molecules

dipole-dipole

59

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

brackets, outside

60

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

B--->I because B--->F(2.0) is ionic

61

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)

Mg (3s)
closest to the nucleus

62

atoms are ____ stable alone than combined with other atoms
why

less
they have to use energy to combine therefore become more stable

63

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

nonpolar, polar, nonpolar, polar

64

what makes a bond polar (covalent)
if the bond occurs between two ___ nonmetals

different

65

what makes a molecule asymmetrical?
if there are ____________ around the central atom and/or if the surrounding atoms are different ______

lone pairs, elements

66

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

ionic compounds

67

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

covalent (molecular) compounds

68

ionic compounds minimize PE by organizing into _____

crystals