Particles, antiparticles and photons

Question 1

What is the antiparticle of K minus?

Answer 1

K plus

Question 2

After the process of pair production, what does the positron then go on to do?

Answer 2

The positron comes into contact with an electron and they annihilate each other. This releases two high energy gamma photons.

Question 3

What is the quark structure of an antiproton?

Answer 3

Question 4

What is the formula for the energy of a photon, if given frequency?

Answer 4

E = hf

E= Energy in J

h= Planck’s constant

6.63 x 10^-34 Js

f= frequency in Hz

Question 5

What is the formula for the energy of a photon, if given wavelength?

Answer 5

E= hc/ λ

E = enegy in J

h = Planck’s constant

c = Speed of light

3 x 10^8 m/s

λ = wavelength in m.

Question 6

Why are photons virtual?

Answer 6

1) We can’t see them directly
2) If we intercepted them using a detector, we would stop the force from working.

Question 7

What is the electron’s antiparticle?

Answer 7

positron

Question 8

The antiparticle of the proton

Answer 8

antiproton

Question 9

The antiparticle of the neutron.

Answer 9

antineutron

Question 10

The antiparticle of the neutrino

Answer 10

antineutrino

Question 11

What is rest energy?

Answer 11

The energy needed to make a particle or the energy released if a particle is destroyed.

Question 12

Convert 1 eV into Joules.

Answer 12

1 x 1.6 x 10^-19

Question 13

What is annihilation?

Answer 13

If a particle and antiparticle meet they smash and create energy.

Question 14

What is pair production?

Answer 14

Energy goes in, creating a particle and antiparticle.

Question 15

What is a practical use of annihilation?

Answer 15

PET scans: it is positron annihilation.