P1 - Matter and Radiation

Question 1

What is an isotope?

Answer 1

An element with a different number of neutrons and the same number of protons

Question 2

Specific charge equation

Answer 2

Specific charge = Q/M

Question 3

What are the different subatomic particles in an oxygen 8/16

Answer 3

16 - nucleon number (protons + neutrons)
8 - number of protons

Question 4

What is the strong nuclear force

Answer 4

The force that holds together the protons in a nucleus (overcomes the electrostatic force of repulsion)

Question 5

What is an Alpha particle

Answer 5

2 protons 2 neutrons - highly ionising due to high kinetic energy

Question 6

Alpha particle decay equation

Answer 6

X -> Z + a (alpha particle) - subtract from top and bottom for Z

Question 7

What is a Beta- particle

Answer 7

1 electron from the nucleus (neutron into proton)

Question 8

Beta- decay equation

Answer 8

X -> Y + e(-) + _Ve (anti). - Add 1 to proton number

Beta minus decay includes an anti electron neutrino - (_Ve)

Question 9

What is a Beta+ particle

Answer 9

A positron emission (Proton into a neutron)

Question 10

What happens during Beta+ decay

Answer 10

In the nucleus a proton turns into a neutron (lowering atomic number by 1), the nucleus emits a fast moving positron particle and a neutrino (Ve)

Question 11

What is Gamma radiation (y)

Answer 11

Electromagnetic radiation emitted by unstable nucleus, has no mass, no charge but is very penetrating

Question 12

What is Electron capture

Answer 12

• Proton absorbs an electron from inner electron shell to become a neutron
• Emits a neutrino
• Atomic number decreases by one

Question 13

What is meant by rest energy

Answer 13

The energy in a particle that is stationary

Question 14

Anti particles and properties

Answer 14

• They have opposite charge from their counterparts (if there is one)
• They have the same rest mass

Question 15

Mega electron volt (MeV)

Answer 15

amount of energy required for 1 electron to move across a potential difference of 1 volt

Question 16

1 MeV

Answer 16

= 1.60x10^-13 coloumbs

Question 17

What is particle annihilation?

Answer 17

When a particle meets its antiparticle they annihilate
Particle mass + kinetic energy -> radiation energy (proton) , 2 produced

Question 18

Energy of photon produced by annihilation equation

Answer 18

E0=hFmin
E0 = rest mass

Question 19

What is pair production?

Answer 19

The opposite of annihilation,
1 proton -> particle + antiparticle

Minimum energy of photon needed
= hFmin=2E0

Question 20

What are the fundamental interactions?

Answer 20

Gravity, Electromagnetic, Strong nuclear, Weak nuclear

Question 21

What do Feynman diagrams represent and what do they do?

Answer 21

• Represents fundamental forces
• Visualises particle interactions including exchange particles

Question 22

What are Exchange particles?

Answer 22

Used to explain the interactions and outside of these diagrams ‘do not do anything’

Question 23

Drawing Feynman diagrams

Answer 23

• Particles are lines with direction (arrows)
• Exchange particles are squiggly lines (virtual)
• Distance (x-axis), time (y-axis)