Chapter 7 Homework

Question 1

An incandescent light bulb gives off much more heat than a fluorescent light bulb, but appears dimmer than the fluorescent light bulb. Based on this information, what can you conclude about the fluorescent light bulb?

Answer 1

It emits less infrared light than the incandescent bulb.

Question 2

A radio wave has a period of 4.76 × 10^−7 s. What is its wavelength?

Answer 2

143 m

Question 3

A solution absorbs light with frequencies between 6.17 × 10^14 s−1 to 5.98 × 10^14 s−1. What can you conclude about the solution based on this information and the following table?

Answer 3

The solution absorbs blue-green light.

Question 4

Suppose you are in a room in which the only light source emits wavelengths of green light and no other colors. What color will an apple that appears red in white light will appear in this room?

Answer 4

black

Question 5

An aqueous solution is used in an absorption experiment. 1 mL of the solution absorbs 50% of the red light shined through it. How will this percentage be affected if enough water is added to reduce the concentration of the solution by half?

Answer 5

1 mL of the diluted solution will absorb less than 50% of the red light shined through it, but greater than 0%.

Question 6

What process at the atomic level is responsible for the production of incandescent light from a hot metal?

Answer 6

Vibrating nuclei within the atom create electromagnetic radiation.

Question 7

What wavelength of light will be emitted from a hydrogen atom when its electron drops from an energy level of n = 4 to an energy level of n = 3?

Answer 7

1.88 × 10^−6 m

Question 8

A beam of neutrons is used in an experiment. If the minimum error in knowing the position of the neutrons is 1.1 × 10−12 m, what is the minimum error in knowing the momentum of the neutrons?

Answer 8

4.8 × 10^−23 kg • m / s

Question 9

Which experimental observation below cannot be predicted by the Bohr model of the hydrogen atom?

Answer 9

The exact frequency at which light is emitted by the Li atom.

Question 10

What is the wavelength of an electron with a velocity of 6.7 × 10^7 m / s?
(The mass of an electron is 9.109 × 10^−31 kg.)

Answer 10

1.1 × 10^−11 m

Question 11

How would a 2s orbital most likely be affected if the angular part of its wave function were to change?

Answer 11

The orbital would probably no longer be spherical.

Question 12

Which of the following symbols represents the probability of finding the electron?

Answer 12

Ψ^2

Question 13

What does the angular solution to the Schrodinger equation disclose?

Answer 13

The shape of electron orbitals.

Question 14

What must occur for an electron to move from a 2s orbital to a 3s orbital?

Answer 14

It must absorb a photon.

Question 15

What is the physical meaning of the square of the wave function, ψ^2?

Answer 15

The square of the wave function is related to the probability of finding a particle at a certain point in space.

Question 16

Which of the following diagrams is a plot of the 2p orbitals?

Answer 16

This drawing represents the p orbitals.

Question 17

Which of the following best defines ionization energy?

Answer 17

Ionization energy is the energy required to remove an electron from an atom

Question 18

Determine the wavelength of light having energy of 2.25 × 10^−19 J.

Answer 18

8.83 × 10^−7 m

Question 19

What frequency of light would cause the electron of a Li 2+ ion to be ejected from the 1s orbital? The energy needed to remove this electron is 1.96 × 10^−17 J.

Answer 19

2.96 × 10^16 s−1

Question 20

Why doesn’t Schrödinger’s equation for the hydrogen atom work for the lithium atom?

Answer 20

Schrödinger’s equation for the hydrogen atom only works for single electron species. It does not take into account the interaction between the electrons in multi-electron species.