12 Quantum and Nuclear Physics

Question 1

How much Energy converts to a mass of 1u?

Answer 1

=> using E=mc^2 m=1u E = 1u x c^2 =1.6605402 x 10^-27 x (3.0 x 10^8)^2J = 1.49239 x 10^-10J

Question 2

How to calculate mass difference △m?

Answer 2

△m = Total mass (of reactants) - Total mass (of products)

Question 3

How do you know if energy is released in a decay or any other reaction?

Answer 3

By calculating △m - If △m is positive - energy will be released and decay will occur -if △m is negative - reactants will not react and reaction can only occur if energy is supplied to reactants

Question 4

The Unit of a Quantity of energy released is? How is it calculated?

Answer 4

Q = Quantity of energy released Q= △m x 931.5MeV

Question 5

What form is of energy is Q released in?

Answer 5

Kinetic energy

Question 6

What is transmutation of nitrogen?

Answer 6

something

Question 7

Describe nuclear fusion.

Answer 7

Fusion is the process where two light nuclei combine together releasing vast amounts of energy.

Question 8

Describe nuclear fission.

Answer 8

Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei

Question 9

What happens during nuclear fission

Answer 9

• Splitting of heavy particles - Produce neutrons - Chain reactions are self-sustaining - for a reaction to continue, minimum mass is required.(critical mass) - Chain reactions are an induced process

Question 10

What happens during nuclear fusion

Answer 10

• Joining two light nuclei into a heavier one with production of energy. - It’s used in energy production in nuclear power plants.

Question 11

What is a Rutherford, Geiger and Masden experiment?

Answer 11

At Rutherford’s behest, Geiger and Marsden performed a series of experiments where they pointed a beam of alpha particles at a thin foil of metal and measured the scattering pattern by using a fluorescent screen.

Question 12

How did the Rutherford, Geiger and Masden experiment prove the discovery of the nucleus.

Answer 12

This was deduced by measuring how an alpha particle beam is scattered when it strikes a thin metal foil.

Question 13

What are elementary particles?

Answer 13

A particle is called elementary if its not made out of any smaller component particles.

Question 14

What are the 3 classes of elementary particles:

Answer 14

1. Quarks e.g.(up, down, bottom, strange,…) 2. Leptons e.g. (electron, electron neutrino, muon, …) 3. Exchange particles e.g.(

Question 15

What are the 6 types of quarks?

Answer 15

1. up (u) (2/3) 4. bottom (b) (-1/3) 2. charm (c) (2/3) 5. strange (s) (-1/3) 3. top (t) (2/3) 6. down (d) (-1/3)

Question 16

What are anti-particles of quarks?

Answer 16

They are particles that have the same mass but their properties are opposite. (They equal each other out in terms of charge). These are shown by putting a bar, like this _, on top of the letter like so, ū,…

Question 17

Which two ways are used to form hadrons.

Answer 17

1. Baryon - combination of 3 quarks. 2. Meson - combination of quark and anti-quark

Question 18

Protons are baryons made up of?

Answer 18

3 quarks (u, u, d)

Question 19

Neutrons are baryons made up of?

Answer 19

3 quarks (u, d, d)

Question 20

What is a baryon number?

Answer 20

The baryon number is a description of properties of quarks.

Question 21

How is the baryon used?

Answer 21

Each quark has a baryon number, B. That is +1/3 for each quark and -1/3 for each anti-quark. This is used to calculate the baryon number of hadrons, add the baryon numbers of the quarks in the hadron. e.g. Cut = +1/3+1/3+1/3 = +1 Ud = +1/3-1/3 = 0

Question 22

What baryon number do baryons and anti baryons have?

Answer 22

Baryons = +1 Anti-Baryons = -1

Question 23

What baryon number do mesons have?

Answer 23

Mesons = 0 Because Mesons = anti-quark + quark

Question 24

What are the six types of Leptons?

Answer 24

Name Charge electron e^- -e electron neutrino V˅e 0 muon μ^- -e muon neutrino V˅μ 0 tau τ^- -e tau neutrino V˅τ 0

Question 25

What is a exchange particles?

Answer 25

An exchange particle is a virtual particle that mediates the interaction between two other particles.