CHEM 18 1st DEPARTAMENTAL EXAM

Question 1

periodic oscillation by which energy is transmitted through space.

Answer 1

wave

Question 2

the distance between two corresponding points in a wave—between the midpoints of two peaks or two troughs

Answer 2

Wavelength (λ)

Question 3

number of oscillations that pass a

particular point in a given period of time.

Answer 3

frequency (ν)

Question 4

defined as half the peak-to-trough height

Answer 4

amplitude

Question 5

• distance traveled by a wave per unit time

- measured in meters per second (m/s)

Answer 5

speed (v)

Question 6

energy that is transmitted, or radiated, through space in the form of periodic oscillations of electric and magnetic fields

Answer 6

Electromagnetic radiation

Question 7

• contradict the theories of classical physics

- electromagnetic radiation whose wavelength and color that depends on the temperature of the object

Answer 7

blackbody radiation

Question 8

classical physics could not explain the sharp decrease in the intensity of radiation emitted at shorter wavelengthswhich was referred to as _______________

Answer 8

ultraviolet catastrophe

Question 9

explained the ultraviolet catastrophe by proposing that the energy of electromagnetic waves is quantized rather than continuous.

Answer 9

Max Planck

Question 10

(A phenomenon in which electrons are ejected from the surface of a metal that has been exposed to light).

Answer 10

photoelectric effect

Question 11

(a principle that matter and energy have properties typical of both waves and particles

Answer 11

wave–particle duality

Question 12

states that the uncertainty in the position of a particle (Δx) multiplied by the uncertainty in its momentum (Δ[mv]) is greater than or equal to Planck’s constant divided by 4π:

Answer 12

Heisenberg uncertainty

Question 13

developed wave mechanics

Answer 13

Erwin Schrödinger

Question 14

mathematical technique that describes the relationship between the motion of a particle that exhibits wavelike properties (such as an electron) and its allowed energies

Answer 14

wave mechanics,

Question 15

three quantum numbers

Answer 15

n, l, and ml

Question 16

tells the average relative distance of an electron from the nucleus:
n = 1, 2, 3, 4, …

Answer 16

principal quantum number

Question 17

• second quantum number

- describes the shape of the region of space occupied by the electron

Answer 17

azimuthal quantum number (l).

Question 18

• third quantum number

- describes the orientation of the region in space occupied by an electron with respect to an applied magnetic field

Answer 18

magnetic quantum number (ml)

Question 19

Each wavefunction with an allowed combination of n, l, and ml values describes an

Answer 19

atomic orbital

Question 20

the number of protons in the nucleus

Answer 20

nuclear charge Z

Question 21

No two electrons in an atom can have the same values of all four quantum numbers (n, l, ml, ms).

Answer 21

Pauli exclusion principle:

Question 22

The electron moves around the nucleus in circular orbits that can have only certain allowed radii.

Answer 22

Bohr’s Model