Deck 29: Atoms and Molecules

Question 1

A hydrogen atom is in its n = 2 excited state when its electron absorbs 9.5 eV in an interaction with a photon.What is the energy of the resulting free electron?

A)5.1 eV
B)6.6 eV
C)6.9 eV
D)7.6 eV

Answer 1

5.1 eV

Question 2

Light excites atomic hydrogen from its lowest level to the n = 12 level.What is the energy of the light?

A)13.7 eV
B)32.2 eV
C)61.4 eV
D)91.8 eV

Answer 2

13.7 eV

Question 3

The electron in a hydrogen atom is infinitely distant at zero potential energy and is at an average radius of ao = 0.0529 nm when bound by 13.6 eV.A barely bound H atom may have an average radius as large as a bacterium,R = 14 μm.What is the nearest principal quantum number in this state?

A)514
B)51
C)16
D)264,650

Answer 3

514

Question 4

In the spectrum of hydrogen the lines obtained by setting m = 1 in Balmer's formula is called the Lyman series.Calculate the wavelength of the spectral line of the 16th member of the Lyman series.

A)91.6 nm
B)371 nm
C)102 nm
D)83.2 nm

Question 5

The shortest wavelength of a photon that can be emitted by a hydrogen atom,for which the initial state is n = 3,is closest to:

A)820 nm
B)850 nm
C)880 nm
D)910 nm
E)940 nm

Question 6

The longest wavelength of a photon that can be emitted by a hydrogen atom,for which the initial state is n = 3,is closest to:

A)550 nm
B)575 nm
C)600 nm
D)625 nm
E)650 nm

Question 7

The shortest wavelength of a photon that can be emitted by a hydrogen atom,for which the initial state is n = 12,is closest to:

A)92 nm
B)82 nm
C)72 nm
D)62 nm
E)52 nm

Question 8

An atom has completely filled inner shells and a single valence electron in an excited p state.The filled inner shells have an orbital momentum equal to zero.The magnitude of the orbital angular momentum of the atom is closest to:

A)1.0
B)1.2
C)1.4
D)1.7
E)2.0

Question 9

The longest wavelength of a photon that can be emitted by a hydrogen atom,for which the final state is n = 9,is closest to:

A)39,000 nm
B)22,000 nm
C)7400 nm
D)16,000 nm
E)28,000 nm

Question 10

A hydrogen atom is excited to the n = 10 level.Its decay to the n = 4 level is detected in a photographic plate.What is the frequency of the light photographed?

A)1.73 × 10¹⁴ Hz
B)1740 Hz
C)1740 nm
D)1.46 × 10^-9 km

Question 11

Radio astronomers often study the radiation emitted by a hydrogen atom from a transition between the two hyperfine levels associated with the ground state.This radiation has a wavelength of 21 cm.What is the energy difference between the hyperfine levels?

A)5.92 × 10^-6 eV
B)5.92 × 10^-25 J
C)1.66 × 10^-24 J
D)4.73 × 10^-25 J

Question 12

The energy required to remove the electron from a hydrogen atom in the n = 11 state is closest to:

A)0.11 eV
B)0.094 eV
C)0.080 eV
D)0.17 eV
E)0.14 eV

Question 13

One of the emission lines described by the original version of Balmer's formula has wavelength 372 nm.What is the value of n in Balmer's formula that gives this emission line?

A)14
B)15
C)16
D)17

Question 14

Light shines through atomic hydrogen gas.It is seen that the gas absorbs light readily at a wavelength of 91.33 nm.What is the level to which the hydrogen is being excited by the absorption of light of this wavelength? Assume that the most of the atoms in the gas are in the lowest level.

A)25
B)27
C)22
D)32

Question 15

Find the energy of the photon emitted when an electron drops from the n = 20 state to the n = 7 state in a hydrogen atom.

A)0.244 eV
B)0.263 eV
C)0.283 eV
D)0.302 eV

Question 16

Calculate the orbital Bohr radius of the n = 3 excited state in a hydrogen atom.

A)0.476 nm
B)0.159 nm
C)0.381 nm
D)0.548 nm

Question 17

A hydrogen atom makes a downward transition from the n = 20 state to the n = 5 state.Find the wavelength of the emitted photon.

A)2.43 μm
B)1.46 μm
C)1.94 μm
D)2.92 μm

Question 18

What is the wavelength of the light emitted by atomic Hydrogen according to Balmer's formula with m = 3 and n = 8?

A)955 nm
B)389 nm
C)1950 nm
D)384 nm

Question 19

A hydrogen atom is excited to the n = 6 level.Its decay to the n = 2 level is detected in a photographic plate.What is the wavelength of the detected emission?

A)410 nm
B)93.8 nm
C)1090 nm
D)93.1 nm

Question 20

What is the frequency of the light emitted by atomic Hydrogen according to Balmer's formula with m = 8 and n = 12?

A)2.86 × 10¹³ Hz
B)10,500 Hz
C)5830 nm
D)5.83 × 10^-6 m

Question 21

It is impossible for an electron to lose its spin angular momentum.

Question 22

In atoms having two or more electrons,no two electrons can have the same value for all four quantum numbers.

Question 23

In atoms having more than one electron,electrons can only make transitions for which the l quantum number changes by one unit.

Question 24

The electron cloud of an atom is formed because the electron spreads out in space.

Question 25

All atoms of a given element contain exactly the same number of protons in their nucleus,but they may have different numbers of neutrons.

Question 26

When collisional excitation occurs,an electron collides with an atom and transfers all of its energy to that atom.

Question 27

¹⁴C and ¹⁴N both contain 8 neutrons in their nuclei.

Question 28

When stimulated emission occurs,the emitted photon and the incident (stimulating)photon have exactly the same energy and travel in the same direction.

Question 29

In spontaneous emission,the electrons all spontaneously emit photons of the same wavelength.

Question 30

All stationary states of the hydrogen atom for which n = 4 have the same energy.

Question 31

The number of electrons in the nucleus is equal to the number of protons.

Question 32

Although the electron has an inherent spin angular momentum,this does not mean that it is actually a spinning ball of matter.

Question 33

According to the Bohr model of the atom,an electron can only jump from a high to a low energy state if it emits a photon whose energy is the same as the energy difference between those two states.

Question 34

How many 3d electron states can an atom have?

A)0
B)4
C)6
D)8
E)10

Question 35

The word "laser" is taken from Light Amplification by Stimulated Emission of Radiation.What is meant by "stimulated"?

Question 36

Which of the statements below is true?

A)For a particular shell,an electron in a hydrogen atom with a higher angular momentum is more likely to be found in a smaller range of distances from the proton.
B)For a particular shell,an electron in a hydrogen atom with a higher angular momentum is more likely to be found in a larger range of distances from the proton.
C)For a particular shell,an electron in a hydrogen atom with a higher angular momentum will have a higher mechanical energy.
D)For a particular shell,an electron in a hydrogen atom with a higher angular momentum is more likely to be found farther from the proton.

Question 37

Do all transitions (excluding fine and hyperfine transitions)that end up in the ground state of hydrogen give ultraviolet light? Why?

Question 38

How many 2d electron states can an atom have?

A)0
B)4
C)6
D)8
E)10

Question 39

Neon has 10 electrons.The element of next higher Z that has chemical properties very similar to those of neon has Z equal to:

A)11
B)17
C)18
D)19
E)36

Question 40

No two distinct atoms produce the same emission spectrum.

Question 41

The Bohr model of the hydrogen atom was not able to explain

A)the cause of why some emission lines were brighter than other emission lines.
B)the wavelengths of the emission lines in the ultraviolet range.
C)the wavelengths of the emission lines in the infrared range.
D)None of the above;the Bohr model explained all of these features.

Question 42

In Bohr's model of the hydrogen atom,electrons orbiting the proton with a high orbital radius have

A)less kinetic energy,more potential energy,and more mechanical energy than those with a low orbital radius.
B)less kinetic energy,more potential energy,and the same mechanical energy than those with a low orbital radius.
C)more kinetic energy,less potential energy,and more mechanical energy than those with a low orbital radius.
D)less kinetic energy,less potential energy,and less mechanical energy than those with a low orbital radius.

Question 43

An electron and a proton are both moving such that their kinetic energy is roughly 100 eV.How do the speeds of the particles compare?

A)The electron is moving about 30 times faster than the proton.
B)The electron is moving about 1000 times faster than the proton.
C)The electron and proton are moving about the same speed.
D)The proton is moving about 30 times faster than the electron.

Question 44

How many electrons can be found with principal quantum number n = 3 in a suitably heavy atom?

A)18
B)6
C)20
D)9

Question 45

Suppose Rutherford were able to somehow control the speed of the alpha particles he fired toward the gold nucleus.If he were able to double the speed of the alpha particles,the ones that are scattered backwards would get __________ times closer to the gold nucleus.

A)two
B)three
C)four

Question 46

Consider an atom with the electron configuration 1s²2s²2p⁶3s²3p⁶.Which of the following is an accurate statement concerning this atom?

A)The atomic number of this atom is Z = 11.
B)This atom is in an excited state.
C)This atom has a non-zero angular momentum.
D)This atom is most likely to give rise to an ion with charge +2e.
E)This atom would probably be very inert chemically.

Question 47

The correct ground state electron configuration of boron (Z = 5)is:

A)1s²2s²2p
B)1s²2s²p³
C)1s²1p²2s
D)1s²2p²3s
E)1s²2p³

Question 48

What is the greatest magnitude of the orbital angular momentum L that you can find in a state with n = 6?

A)5.48
B)5.92
C)6
D)6.48