Quantum Theory, Quantum Mechanics

Question 1

This theory states that that atoms or molecules emit energy in certain discrete quantities called “quanta or quantum.”

Answer 1

Quantum theory

Question 2

Who proposed the quantum theory?

Answer 2

Max Planck

Question 3

What is the equation for energy E of a single quantum of energy?

Answer 3

E = hv where (h) is called Planck’s constant and (v) is the frequency of radiation

Question 4

A vibrating substance by which energy is transmitted

Answer 4

Wave

Question 5

The distance between identical points on successive waves

Answer 5

Wavelength (λ ; lambda)

Question 6

Number of waves that pass through a particular point in 1 s.

Answer 6

Frequency (ν ; nu)

Question 7

Vertical distance from the midline of a wave to the peak or trough

Answer 7

Amplitude

Question 8

The point at which the amplitude is zero

Answer 8

Node

Question 9

It is defined as the product of wavelength and frequency (λν)

Answer 9

speed (u)

Question 10

Defined as a wave with an electric and magnetic field components

Answer 10

Electromagnetic waves

Question 11

Emission and transmission of energy in the form of electromagnetic waves

Answer 11

Electromagnetic radiation

Question 12

What is the speed of electromagnetic waves (aka light)?

Answer 12

c = 2.99792458 × 10^8 / 3.0 x 10^8 m/s

Question 13

Shortest waves with the highest frequency

Answer 13

Gamma rays

Question 14

An interference that occurs when two waves are in phase/identical, resulting in a pattern made from the addition of the two waves

Answer 14

Constructive interference

Question 15

An interference that occurs when two waves are out of phase, resulting in the perfect cancellation of the two waves

Answer 15

Destructive interference

Question 16

Smallest quantity of energy that can be emitted or absorbed in the form of electromagnetic radiation

Answer 16

Quantum

Question 17

What is the value of Planck’s constant?

Answer 17

6.63 × 10^−34 J

Question 18

A phenomenon in which electrons are ejected from the surface of certain metals exposed to light of at least a certain minimum frequency

Answer 18

Photoelectric effect

Question 19

Below the threshold frequency no electrons were ejected no matter how intense the light

Answer 19

TRUE

Question 20

The number of electrons
ejected was proportional to the intensity (or brightness) of the light, but the energies of the
ejected electrons were not.

Answer 20

TRUE

Question 21

It is the particle of light, with an energy E using the same form as Planck’s equation

Answer 21

Photons

Question 22

The energy that binds the electrons in the metal

Answer 22

Work function Φ

Question 23

In the photoelectric effect, no electrons are ejected when the frequency of light is below the threshold frequency of a metal. When the frequency of light is above the threshold frequency, electrons are ejected with kinetic energy that increases with increasing frequency of light.

Answer 23

TRUE

Question 24

It is the state where an atom absorbs energy and its electrons form an orbit to another with a higher energy

Answer 24

Excited

Question 25

The state after an electron falls to an orbit of low energy / lowest energy state of a system

Answer 25

Ground state

Question 26

The more intense the light, the greater the number of electrons emitted by the target metal; the higher the frequency of the light, the greater the kinetic energy of the ejected electrons

Answer 26

TRUE

Question 27

What is represented by the value 2.18 x 10^-18 J

Answer 27

Rydberg constant for the hydrogen atom

Question 28

How does Bohr’s model of the atom explain the line spectrum of hydrogen?

Answer 28

Bohr tells us that the electrons in the Hydrogen atom can only occupy discrete orbits around the nucleus (not at any distance from it but at certain specific, quantized, positions or radial distances each one corresponding to an energetic state of your H atom) where they do not radiate energy. When the electron moves from one allowed orbit to another it emits or absorbs photons of energy matching exactly the separation between the energies of the given orbits (emission/absorption spectrum).

Question 29

The difference between the energies of the initial and final states is denoted by?

Answer 29

ΔE = Ef− Ei

Question 30

What is meant by the dual nature of an electron?

Answer 30

It can be considered both as a wave and as a particle

Question 31

It states that it is impossible to know simultaneously both the momentum and position of a particle with certainty

Answer 31

Heisenberg Uncertainty Principle

Question 32

How does the Heisenberg principle contradict Bohr's atomic model?