Book: Ch. 7

Question 1

Define: electromagnetic radiation

Answer 1

Visible light, x-rays, radio waves, and microwaves are examples. Basically photons.

Question 2

Define: frequency (ν)

Answer 2

Number of complete waves or cycles that pass a given point per second, usually expressed by the unit s⁻¹ or hertz (Hz)

Question 3

Define: wavelength (λ)

Answer 3

Distance between any point on a wave and the corresponding point on the next crest or trough of the wave. The distance the wave travels during one cycle. Usually measured in nm.

Question 4

Define: speed of light (c)

Answer 4

c = νλ = 3.00×10⁸ m/s

Question 5

Define: amplitude

Answer 5

Height of the crest. For electromagnetic waves, this corresponds to the intensity of the radiation.

Question 6

Define: electromagnetic spectrum

Answer 6

The types of electromagnetic radiation arranged in order of increasing wavelength.

Question 7

Define: ultraviolet radiation (UV)

Answer 7

Spectrum of electromagnetic radiation to the left of visible light on the spectrum.

Question 8

Define: infrared radiation (IR)

Answer 8

Spectrum of electromagnetic radiation to the right of visible light on the spectrum.

Question 9

Define: refraction

Answer 9

When a wave passes from one medium to another, it refracts: it changes direction and the wave continues at a different angle.

Question 10

Define: diffraction

Answer 10

When a wave strikes the edge of an object, it bends around it. This is diffraction.

Question 11

What is the equation for the energy of a photon?

Answer 11

E = nhν, where n is a quantum number taking values of positive integers, and h is Planck’s constant.

Question 12

Define: Planck’s constant

Answer 12

h = 6.626×10⁻³⁴ [J s]

Question 13

What is the relationship between the change in energy of a photon and the properties of light is emits?

Answer 13

∆E atom = E emitted radiation = hν = hc/λ

Question 14

Define: photoelectric effect

Answer 14

A phenomenon explained by Einstein with the introduction of the photon theory of light.

Question 15

Define: photon

Answer 15

A single particle of light.

Question 16

What is the energy of a photon?

Answer 16

E photon = hv = ∆E atom

Question 17

What is the Rydberg equation?

Answer 17

1/λ = R(1/n₁² - 1/n₂²)

Question 18

Define: stationary states

Answer 18

The H atom has only certain energy levels. Bohr called these the stationary states.

Question 19

How is the energy level between two different states of the H atom found?

Answer 19

∆E = -2.18×10⁻¹⁸ (1/n_f² - 1/n_i²)

Question 20

Define: de Broglie wavelength

Answer 20

Equation λ = h/mu, where u is speed of the object. Basically gives the wavelength of an object, under the assumption that matter behaves like a wave.

Question 21

Define: uncertainty principle

Answer 21

It is impossible to know simultaneously the position and momentum of a particle, so m∆x∆u ≥ h/4π

Question 22

Define: principal quantum number (n)

Answer 22

A positive integer giving the relative size of the orbital an electron has as well as its energy level.

Question 23

Define: angular momentum quantum number (l)

Answer 23

An integer from 0 to n - 1. n sets the limit on what values l can take. l is related to the shape of the orbital.

Question 24

Define: magnetic quantum number (m_l)

Answer 24

An integer from -l through 0 to l. Number of m_l values = 2l+1 = number of orbitals for a given l. Prescribes three-dimensional orientation of the orbital in the space around the nucleus.

Question 25

Define: levels and sublevels for atoms

Answer 25

Level: aka shells of an atom. Given by n value.
Sublevels: subshells. Given by the l value. l = 0 is s sublevel, 1 is p, 2 is d, 3 is f.