Atomic and Nuclear Phenomena

Question 1

How does the work function relate to the energy necessary to emit an electron from a metal

Answer 1

The work function describes the minimum amount of energy necessary to emit an electron. Any additional energy from a photon will be covered to excess kinetic energy during the photoelectric effect.

Question 2

What does the threshold frequency depend on?

Answer 2

The threshold frequency depends on the chemical composition of a material (that is, the identity of the metal).

Question 3

What electrical phenomenon results from the application of the photoelectric effect?

Answer 3

The accumulation of electrons creates a current during the photoelectric effect

Question 4

What determines the absorption spectrum of a single atom

Answer 4

The energy differences between ground-state electrons and higher-level electron orbits determine the frequencies of light a particular material absorbs (its absorption spectrum).

Question 5

During which electronic transition is photon emission most common

Answer 5

When electron transitions from higher-energy state to lower-energy state, they will experience photon emission

Question 6

What causes fluorescence

Answer 6

Fluorescence is a special stepwise photon emission in which an excited electron returns to the ground state through one or more intermediate excited states. Each energy transition releases a photon of light. With smaller energy transitions than the initial energy absorbed, these materials can release photons of light in the visible range.

Question 7

Strong Nuclear Force

Answer 7

It is one of the 4 primary forces and provides the adhesive force between the nucleons (protons and neutrons) within the nucleus
- strongest but work only short distances

Question 8

Mass Defect

Answer 8

Amount of mass converted to energy during nuclear fission
- Mass defect is the apparent loss of mass when nucleons come together (bounded), as the mass is converted to energy. This energy is called binding energy

Question 9

Binding energy

Answer 9

The amount of energy that is released when nucleons (protons and neutrons) bind together.
- the more binding energy per nucleon released the more stable the nucleus

Question 10

What are the 4 fundamental forces of nature

Answer 10

1. Strong nuclear force
2. Weak Nuclear force
3. Electrostatic force
4. gravitational force

Question 11

How does the mass defect relate to the binding energy

Answer 11

Mass defect is related to binding energy such that there is a transformation of nuclear matter to energy with a resultant loss of matter. They are related by the equation E=mc^2

Question 12

True or false: both nuclear fission and fussion both release energy?

Answer 12

True

Question 13

Fission

Answer 13

Occurs when a large nucleus splits into small nuclei

Question 14

Fussion

Answer 14

Occurs when small nuclei combine into larger nuclei

Question 15

Alpha Decay

Answer 15

Emission of 4,2He
Z: -2
A:-4

Question 16

Beta negative and positive decay

Answer 16

Emission of electron
Negative
Z: +1
A:0
Positive
Z:-1
A:0

Question 17

Gamma decay

Answer 17

emission of gamma ray
Z:0
A:0

Question 18

Electron capture

Answer 18

Nothing (absorption of electron from inner shell of nucleus)
Z:-1
A:0

Question 19

How many half life are needed to complete decay of a radioactive sample?

Answer 19

because the amount remaining is cut in half after each half-life, the portion remaining will never quite reach zero. This is mostly theoretical consideration; “all” of the sample is considered to have decayed after 7 to 8 half-life

Question 20

Which type of nuclear decay would be detected in an atomic absorption spectrum?

Answer 20

Because gamma radiation produces electromagnetic radiation (rather than nuclear fragments), it can be detected on an atomic absorption spectrum