• Interaction Of Particles

Question 1

What is the formula for momentum?

Answer 1

Mass x Velocity

Question 2

What causes the electromagnetic force between two charged objects?

Answer 2

Virtual photons

Question 3

Why are virtual photons, “virtual”?

Answer 3

• They cannot be detected directly.

* If intercepted, the force would stop acting.

Question 4

What happens when two objects interact?

Answer 4

• They exert equal and opposite forces on each other.

* Momentum is transferred between the objects by these forces.

Question 5

What force holds the neutrons and protons together in an nucleus?

Answer 5

Strong nuclear force.

Question 6

What does strong nuclear force not do?

Answer 6

• Cause beta decay.

Question 7

Why does electromagnetic force not cause beta decay?

Answer 7

Neutron is uncharged.

Question 8

What force causes changes in the nucleus?

Answer 8

Weak Nuclear Force

Question 9

Why does weak nuclear force have to be ‘‘weak’’?

Answer 9

If it was any stronger than the strong nuclear force, it would affect stable nuclei, therefore it must be weaker than the strong nuclear force.

Question 10

When do neutrinos and anti-neutrino’s interact with other particles?

Answer 10

• Neutrino can interact with a neutron and make it change into a proton. A B+ particle is created and emitted as a result of the change ( electron ).
• Anti neutrino can interact with a proton and make it change into a neutron. A B+ particle ( positron ) is created and emitted as a result of the change

Question 11

What are the exchange particles in weak nuclear interactions?

Answer 11

W bosons.

Question 12

What are some features of W bosons?

Answer 12

• Have a non zero mass
• Have a very short range ( 0.001 fm )
• Are positively charged ( W+ boson ) or negatively charged ( W- Boson ).

Question 13

What does a W- boson decay into?

Answer 13

• B- Particle

* Antineutrino

Question 14

What does a W+ boson decay into?

Answer 14

• B+ Particle

* Neutrino

Question 15

How does a neutron interact with a neutrino?

Answer 15

• W- boson is the W boson.
• Neutrino becomes B- Particle ( Electron ).
• Neutron becomes a proton

Question 16

How does a proton interact with an anti neutrino?

Answer 16

• W+ boson is the W boson
• Proton becomes a neutron
• Antineutrino becomes a B+ particle ( positron ).

Question 17

What is the process of electron capture?

Answer 17

• Proton in a proton rich nucleus turns into a neutron as a result of interacting through the weak interaction with an inner shell electron from outside the nucleus.

Question 18

How can electron capture take place?

Answer 18

• Proton in a proton rich nucleus turns into a neutron as a result of interacting through the weak interaction with an inner shell electron from outside the nucleus.
• Proton colliding with an electron at a very high speed.

Question 19

Why are photons and W bosons known as force carriers?

Answer 19

They are exchanged when the electromagnetic force and the weak nuclear force act respectively.