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