Particles

Question 1

What are isotopes

Answer 1

Atoms with the same number of protons but different number of neutrons

Question 2

What is the specific charge of a particle

Answer 2

The ratio of its charge to its mass

Question 3

Equation of specific charge

Answer 3

SC = Q/M
Ckg-1 = C/kg

Question 4

What is the strong force responsible for, its range and exchange particle

Answer 4

Responsible for keeping the nucleus together. Range = 1x10^-18 metres
Gluon

Question 5

What are released in alpha decay

Answer 5

2 neutrons and 2 protons

Question 6

Describe beta decay

Answer 6

A neutron decays into a proton and electron - the electron is emitted

Question 7

What are photons

Answer 7

A “packet”/“quantum” of electromagnetic energy

Question 8

Define annihilation

Answer 8

A particle and its antiparticle collide producing two photons
The total energy of the photons = the combined rest mass and Ek of the particle and antiparticle

Question 9

Define pair production

Answer 9

A photon turns into a particle and its antiparticle. The minimum photon energy = twice the rest mass of the particle produced

Question 10

Name the 4 fundamental forces

Answer 10

Gravity, Electromagnetic, Weak force and Strong force

Question 11

What are the gravity, electromagnetic and weak force range

Answer 11

infinite, infinite, 1x10^-18 metres

Question 12

What is the gravity force responsible for and its exchange particle

Answer 12

The attractive force between any two masses
Graviton

Question 13

What is the electromagnetic force responsible for and its exchange particle

Answer 13

Attractive or repulsive between any two charges
Virtual photon

Question 14

What is the weak force responsible for and its exchange particle

Answer 14

Beta decay
W+/W-

Question 15

What is an antiparticle

Answer 15

A particle with the same mass and rest energy but opposing charge

Question 16

What is the difference between hadrons and bosons?

Answer 16

Bosons are fundamental force exchange particles

Question 17

What is the difference between baryons and mesons?

Answer 17

Baryons contain qqq, mesons contain qq

Question 18

What fundamental forces can leptons experience?

Answer 18

Gravity, electromagnetic and weak

Question 19

What is the only stable baryon

Answer 19

proton

Question 20

In which interaction is strangeness NOT conserved?

Answer 20

Weak

Question 21

Quark construct of a proton and a neutron

Answer 21

p = uud
n = udd

Question 22

Quark construct of a pion

Answer 22

π^+ = up and anti-down
π^0 = up and anti-up

Question 23

quark construct of a kaon

Answer 23

k+ = up and anti-strange
k^0 = down anti-strange

Question 24

How does light behave as a particle

Answer 24

Photoelectric effect

Question 25

What is one electron-volt equivalent to in J

Answer 25

1eV = 1.6X10^-19 J

Question 26

What is the ground state

Answer 26

Nearest possible position to the nucleus

Question 27

What are excited states

Answer 27

Energy levels above the ground state but below the ionisation level

Question 28

How can you increase the maximum kinetic energy of a photoelectron

Answer 28

Increase the frequency of the incoming photon/decrease the wavelength

Question 29

Why might electrons not be emitted from a plate

Answer 29

The energy is less than the work function

Question 30

What is the work function

Answer 30

The minimum energy needed to release an electron from the surface of a metal

Question 31

What is ionisation

Answer 31

the energy required to remove one electron from an atom

Question 32

What can cause ionisation/excitation

Answer 32

- collision of photons or electrons - nuclear radiation - heating - passing an electric current through a gas

Question 33

What is excitation

Answer 33

When an electron moves from a lower to a higher energy level within an atom

Question 34

Evidence of light behaving as a wave

Answer 34

Diffraction

Question 35

Evidence for an electron behaving as a particle

Answer 35

deflection in a field

Question 36

Evidence for an electron behaving as a wave

Answer 36

diffraction (particles can't be deflected so electron must be waves)

Question 37

In β– decay what decays

Answer 37

n ===> p + e- + anti-electron neutrino

Question 38

In β+ what happens

Answer 38

p ===> n + e+ + electron neutrino