Chapter 7: Electronic Structure Flashcards Preview

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Flashcards in Chapter 7: Electronic Structure Deck (173):
1

Rutherford's model did not address

how the electrons occupied the space around the nucleus

2

initially, it was assumed that electrons held ... about the nucleus, leading to the ... model of the atom

fixed orbits; planetary

3

under certain conditions, atoms and molecules emit and absorb energy in the form of

light

4

in the late 19th century, physicists knew that light could be described as

waves

5

waves are ... in nature: they...

periodic; repeat at regular intervals of both time and distance

6

any wave is described by its

wavelength, frequency, and amplitude

7

wavelength (λ, ...) is the ...

lambda; distance between one peak to the next

8

in SI system, wavelength is measured in

meters

9

frequency (v, ..) is the number of ...

nu; waves that pass a fixed point in 1 second

10

the SI unit for frequency si ... and is called ..

s^-1; hertz (Hz)

11

amplitude is the ... of a wave

maximum height

12

height of a wave varies between

+Amax and -Amax

13

light waves are called... because they consist of ..., which are perpendicular to ... and to the direction of ...

electromagnetic radiation; oscillating electric and magnetic fields; each other; propagation;

14

the speed at which a wave travels is the product of its

wavelength and frequency

15

the periodic nature of wave motion is not always

easily seen

16

the experimentally measured speed of light shows that all electromagnetic radiation travels at the

same speed in a vacuum, no matter what its wavelength

17

the speed of light in a vacuum is one of the fundamental constants of nature:

3.00 x 10^8 m/s

18

c=

λv

19

the amplitude is the vertical ...

displacement from the undisturbed medium

20

the length of time that it takes for one complete wave to pass a point is

deltat

21

wavelength and frequency are

inversely proportional

22

the human eye can detect only a very small part of the electromagnetic range, called

visible light

23

visible light includes wavelengths from ... to ... nm

400; 700

24

order of colors for visible spectrum:

VIBGYOR

25

shorter wavelengths are

higher in energy

26

amplitude indicates the .. of light source

brightness

27

gamma and x rays are the

shortest wavelengths (highest in energy)

28

radio and microwaves are the

longest wavelengths (smallest in energy)

29

at temperatures greater than absolute zero, matter emits ...., and the emission is referred to as a ...

electromagnetic radiation of all wavelengths; continuum

30

not all wavelengths of light are emitted with

equal intensity

31

the distribution of the intensity of different wavelengths changes with

temperature

32

in 1900, max planck proposed an explanation of the wavelengths emitted by ... that was based on an assumption that violated the classical models of physics

heated objects

33

planck assumed that the particles of matter in the heated objects were ...., and that the amount of energy the particles had was proportional to the ...

vibrating back and forth; frequency at which the particles vibrated

34

planck's equation

E= hv

35

h, ...., is =

planck's constant; 6.626 x 10^-34 J * s

36

because the energy of the vibrating particle has a specific energy, the energy is considered to be

quantized

37

Einstein applied planck's equation to ... and proposed that light behaves as a .... whose value is directly proportional to the ...

light; particle of energy; frequency of the light

38

Einstein essentially proposed that the energy of light was ..., meaning that it could only be a ...

quantized; certain amount

39

photoelectric effect is the process in which electrons are ....

ejected from solid metal when it is exposed to light

40

each metal has a characteristic ...., that is necessary before any ...

minimum frequency; electrons are emitted

41

as the frequency of light increases from the minimum, the kinetic energy of the ejected electrons

alos increases

42

more intense light does not increase the ....., but it does increase the ...

kinetic energy of the electrons; number of electrons emitted

43

Einstein suggested that light not only had wave properties, but could be viewed as a stream of tiny particles, referred to as

photons

44

a ... with an energy of hv must provide enough energy to ...

SINGLE photon; eject an electron

45

some of the energy, hv0, must be used to overcome the ....

attraction the solid has for the electrons

46

equation with hvs and ke

hv = hv0 + KE

47

one photon of light can eject

one electron

48

increasing the intensity of the light source produces more ..., because the number of photons is ...

ejected electrons of the same KE; proportional to the intensity

49

if the energy of the absorbed photon is less than hv0, even with an increased intensity it will only

heat the metal

50

Einstein's explanation in conjunction with planck's theory suggested that each .... was carried by a ...

quantum of energy; particle of light or a photon

51

in the interpretation of the photoelectric effect, electromagnetic radiation is treated as ... instead of ..

particles of light (photons); waves

52

when energy in the form of heat or an electric discharge is added to a sample of gaseous atoms in a process called ..., the atoms can emit some of the ...

excitation; added energy as light

53

spectrum: the ... of the light as a function of ...

intensity; wavelength

54

a heated solid produces a ...., one in which all ... are present

continuous spectrum; wavelengths

55

the light emitted by excited atoms is called a ... because it contains light only at ...

line spectrum; specific wavelengths

56

each element produces a line spectrum that is ... and different from the spectrum of ...

characteristic of that element; any other element

57

wavelengths of all lines in the spectrums given by the

Rydberg equation

58

Rydberg equation:

1/λ=R_H (1/(n_1^2 )-1/(n_2^2 ))

59

n1 and n2 are positive integers with n1 ...

< n2

60

Rh, called the .., has the value of ...

Rydberg constant; 1.097 x10^7 m^-1

61

they hydrogen atom spectrum consists of series of lines that are named after those who discovered them:

Lyman (n1 = 1)
Balmer (n1 = 2)
Paschen (n1 = 3)
Brackett (n1 = 4)
Pfund (n1 = 5)

62

The Rydberg equation accurately predicts the wavelengths ofall observed lines in the

spectrum of hydrogen atoms

63

the discrete line spectra of atoms suggested that electrons exist in

only certain allowed energy levels

64

niels bohr proposed a model for the ... that accounted for the ...

hydrogen atom; observed spectrum of hydrogen

65

bohr assumed that the electron moved in ... around the nucleus

circular orbits

66

bohr assumed that the electron could have only certain values of

angular momentum

67

angular momentum:

momentum of a mass moving in a circle

68

bohr also found that the allowed ... and .... are also quantized

radii; energies

69

En=

(-(2π^2me^4)/h^2)*1/n^2 = -B/ n^2

70

for En, m is the ...., e is the ..., h is ..., and n is a positive integer that indicates ..

mass; charge of electrons; planck's constant; electron's energy level

71

B=

2.18 x 10^-18 J

72

bohr concluded that the energy levels of the electron in a hydrogen atom are

quantized

73

bohr realized that the light emitted by the atom must have energy (hv) that is exactly equal to the difference between the

energies of two of its allowed levels

74

(bohr) Elight= E2 - E1 =

B/n1^2 - B/n2^2

75

as the electron and the H+ nucleus move closer together, the atom becomes..., so the energies of all the allowed states have a ...

more stable (lower in energy); negative sign

76

the energy of an allowed state is proportional to ..., so the energies of the allowed states get ... as n increases

1/n^2; closer together

77

when an electron goes from one quantized energy state to a lower one, the

difference in energy is released as a single photon

78

all of the energy released when an atom goes from one allowed energy state to a lower one is contained in a

single photon of light

79

the electron in the hydrogen atom can also be excited to higher levels by the ...

absorption of a photon

80

the only photons absorbed are those with energy identical to the

energy difference between two allowed states of the atom

81

the grounds state of an atom is its lowest

quantized energy state

82

at normal temperatures, nearly all hydrogen atoms are present in the

ground state

83

thus, the only lines observed in the absorption spectrum of hydrogen atoms are those in the

lyman series

84

momentum=p=

h/λ

85

p =

mv

86

equation--> known as ... λ (in terms of momentum)=

de Broglie equation; h/p = h/mv (m is mass, v is velocity)

87

de Broglie predicted that a particle of matter would have a wavelength that is

inversely proportional to the mass

88

the davisson-germer experiment, which demonstrated that matter exhibited its ..., was a significant step forward in understanding the ...

wave properties and particle properties; properties of the electron

89

diffraction is a property of

waves

90

de Broglie's equation explained the assumption of quantized angular momentum of the electron in the hydrogen atom by suggesting that the electron "wave" in an atom must be a ...., which is a wave that ...

standing wave; stays in a constant position

91

de Broglie's restriction for standing wave expressed in this equation:

2πr= nλ

92

bohr's treatment of the hydrogen atom cannot be extended to

larger atoms

93

Erwin schrodinger devised a wave model to describe the

behavior of the electrons in atoms

94

the electron wave can be described by a mathematical function that gives the .... this function is called a ..., represented by the greek letter psi

amplitude of the wave at any point in space; wave function

95

the square of the wave function gives the ... of finding the electron at any point in space

probability

96

the wave model doesn't conflict with the Heisenberg uncertainty principle because it does not precisely define the

location of the electron

97

he values of quantum numbers are related to the ... and ... of the electron wave and the location of the ...

shape; size; electron in 3d space

98

it is possible to calculate the energy of an electron having each possible

wave function

99

the angular momentum of the electron is also quantized but this is a ...

natural consequence of the wave function

100

schrodinger's wave model is a fundamental idea in the theory called

quantum mechanics

101

the best current description of the electronic structure of the atom treats the electron as a

wave

102

quantum numbers represented by

n, l, and msubl

103

the 3d wave function of an electron is called an

atomic orbital

104

each of the quantum numbers is restricted to certain

whole-number values

105

n refers to the

principal quantum number

106

the principal quantum number gives info about the

distance of the electron from the nucleus

107

all orbitals that have the same value of n are in the same

principal shell

108

the term principal shell (or simply, shell) refers to all atomic orbitals that hae the same value of n, because they all have approx. the same

average distance from the nucleus

109

l refers to the

angular momentum quantum number

110

the possible values of l for a given n are all positive integers from zero up to

n-1

111

angular momentum quantum number describes the

shape of the orbital

112

a subshell contains all orbitals that have the

same values for n and l

113

the notation for a subshell consists of a ..., which is the value of the ..., followed by a ... that identifies the value of the l quantum number

number; n quantum number; lower case letter (s, p, d, or f

114

s, p, d, and f stand for

sharp, principal, diffuse, and fundamental

115

ml refers to the

magnetic quantum number

116

allowed values for ml

-l to l

117

ml quantum number provides info about the

orientation in space of the atomic orbital

118

each subshell consists of one or more

atomic orbitals

119

the fourth quantum number does not directly come from the

wave model

120

ms refers to the

electron spin quantum number

121

the allowed values of m are

+1/2 and -1/2

122

the electron spin does not depend on the values of any of the

other quantum numbers

123

two electrons that have the same spins are ..., whereas electrons with different spins are ...

parallel; paired

124

nodes: regions in space where the probability of finding an electron is exactly

zero

125

as the principal quantum number increases in value, the average distance of the electron from the nucleus ..., and thus the size of the ... increases

increases; contour surface

126

if the principal quantum number is the same, no matter which subshell or orbital the electron occupies, the hydrogen atom has exactly the same

energy

127

the energy of each wave function for any atomic species containing only one electron is given by

En = -(Z^2B)/n^2 (Z is nuclear charge)

128

the different subshells within the same shell of a multielectron atom

do not have the same energy

129

because charges of opposite sign attract each other, the energy of the atom decreases (the atom becomes more ...) as the electron

stable; gets closer to the nucleus

130

energies in multielectron atoms depend on the values of ...

both the n and l quantum numbers

131

in one-electron atoms and ions, the energy depends only on the

value of the n quantum number

132

the single electron in any one-electron species, regardless of its location or the orbital it occupies, is attracted by the

nuclear charge

133

the electron-electron repulsions, known as .., reduce the effect of the positive charge of the nucleus on each electron, thus ...

interelectronic repulsions; influencing its energy

134

the net attraction of the nucleus for n electron at any distance r is reduced, or shielded, by the ....

repulsive forces from the electrons between it and the nucleus

135

effective nuclear charge, Zeff, is the weighted average of the ...., after correction for the shielding of nuclear charge by ... and the ...

nuclear charge that affects an electron in the atom; inner electrons; interelectronic repulsions

136

electron shielding is the result of the influence of .... on the ...

inner electrons; effective nuclear charge

137

to determine the effective nuclear charge for each electron, we need to know whether the other electrons in the atom are between

it and the nucleus

138

although the average distances of the 2s and 2p electrons are about the same, the probability that the electron is close to the nucleus is greater for the ... than for the ...

2s electron; 2p electron

139

the 2s electron penetrates the electron density of the filled 1s shell more than does the 2p electron, so it is influenced by a

greater effective nuclear charge

140

the energy of an s electron is ... than the energy of a p electron in the same shell

lower

141

within any shell, the penetration of the s orbital is always greater than that of the ... orbitals, which in turn, is greater than that of the ... orbitals

p; d

142

within any shell, the subshells increase in energy in the order of

increasing value of the quantum number l

143

different interelectronic repulsive forces affect electrons in different subshells, so the energy of an atom depends on

which subshells are occupied

144

the overlap in the energy of different shells becomes more common as

n increases

145

energy separation between subshells gets quite small in the higher shells, so small changes int eh shielding effects may cause the energy order to

change from one element to the next

146

because the energies of different orbitals depend only on the values of the n and l quantum numbers and not on the value of ml, all of the orbitals in a subshell have

exactly the same energy

147

when orbitals are of exactly the same energy, they are referred to as

degenerate orbitals

148

pauli exclusion principle: no two electrons in the same atom can have teh

same set of all four quantum numbers

149

the pauli exclusion principle is the quantum-mechanical equivalent of saying that two objects cannot

occupy the same space at the same time

150

using the pauli exclusion principle, we find that the maximum number of electrons that can share a single orbital in an atom is

two

151

two electrons in the same orbital are referred to as an ... or ..., because they must have different spins

electron pair; paired electrons

152

when a single electron is in an orbital, it is called an

unpaired electron

153

the restrictions on the quantum numbers and the pauli exclusion principle determines the capacities of ..., ..., and ...

orbitals; subshells; principal shells

154

aufbau principle states that electrons are added to the atom one at a time until the

proper number is present

155

(aufbau principle) as each electron is added, it is assigned the quantum numbers of the

lowest energy orbital available

156

practically all of the atoms in a sample are in the ...at normal temperatures

ground state

157

if one or more of the electrons is in any other allowed orbital of the diagram, the atom is in an

excited state

158

the excited state is of ..., and the atom tends to return to its ground state by ...., often by emitting a ...

higher energy; losing energy; photon of light

159

an excited state is not equivalent to an impossible state, in which ..... of quantum numbers are present

forbidden combinations

160

two electrons in the same orbital must always have .... , represented by "..." and "..." ...

opposite spins; up; down arrows

161

in an orbital diagram, each orbital is represented by a ..., with orbitals in the same subshell shown as ...

box; grouped boxes

162

both ... and ... are used to represent the electrons in atoms

energy-level diagrams; orbital diagrams

163

the electron configuration of an atom is ...; it does not contain the detailed information about ... that an orbital diagram provides

compact; electron spins

164

whenever electrons are added to a subshell that contains more than one orbital, the electrons enter →...

separate orbitals until there is one electron in each; hund's rule

165

two electrons in the same orbital are closer together than they would be if they were in separate orbitals, and they therefore

repel each other more strongly

166

hund's rule states that degenerate orbitals are filled with one electron in each before

any electrons are paired

167

we use hund's rule to write the ground-state electron configurations and orbital diagrams for the elements iwth atomic numbers

7 through 10

168

abbreviated electron configuration: uses ... to represent the partial electron configuration up to the number of electrons for that gas

noble ass

169

abbreviated electron configurations are more convenient for expressing the electron configurations of

heavier atoms

170

anomalous electron configuration are configurations that are the

exceptions

171

the anomalous electron configuration leads to a combination of either ... or a ... and a ...

two half-filled subshells; half-filled; completely filled subshell

172

we cannot predit which atoms will ahve

anamolous electron configurations in advance

173

the total electronic energy of the atom is ... in an anomalous configuration in comparison with a ...

lower; "normal" electron configuration