Waves and Radiation

Question 1

How many fundamental Particles are there and what do they make up

Answer 1

12 and they make up everything

Question 2

what are they also known as and what 2 groups can they be split into.

Answer 2

Fermions

• Quarks
• Leptons

Question 3

how many types of quarks are there

Answer 3

To 1st generation called up and down
– These make up protons and neutrons
To 2nd generation called charm and strange
two 3rd generation called top and bottom

Question 4

Explain what you know about hadrons

Answer 4

Greek for massive
these are Particles made up of quarks
Bayrons – these are made up of three quotes
Mesons –these are made up of a quark and an antiquark pair

Question 5

Explain what you know about Bayrons

Answer 5

Examples include the proton and a neutron
Proton consists of two up and one down quark which equals 1e
neutron consists of two down on one up quark which equals 0e

Question 6

Explain how you know about mesons

Answer 6

they are made up of a quark and an antiquark pair
because of the stairs very unstable
a pion pi+ made of a quark and antiquark pair
Pi+ charge equals 2/3+1/3=1e

Question 7

Explain what you know about Leptons

Answer 7

they are fundamental particles
first generation lepton is electron (-ve)
second generation is muon (-ve)
Third generation is tau (-ve)
all leptons have associated anti particle
both leptons and anti particles have its own neutrino

Question 8

what is the strong force

Answer 8

short range force that hold particles with the same charge together
it holds quarks together to form hadrons
its exchange particles are called gluons because they glue quarks together
the force is so strong that it can overcome the repulsion between the protons in the nucleus

Question 9

what is the weak force

Answer 9

involved in radioactive, beta decay as the weak force is responsible for ‘flavour change’ which is the neutron turning into a up quark
exchange particles are called w and z bosons
extremely short force range only acting within the hadron

Question 10

what is the electromagnetic force

Answer 10

this stops electrons from flying out of the atom and its exchange particle is the photon

Question 11

what is radioactive decay

Answer 11

the breakout of the nucleus to release energy and matter

this allows the unstable nuclei to become stable

Question 12

what three types of radiation can be emittedd

Answer 12

Alpha
Beta
Gamma

Question 13

what is the nature of alpha and beta particles and gamma rays

Answer 13

alpha- helium nucleus
beta- fast electron
gamma ray- high frequency EM wave

Question 14

what is alpha decay

Answer 14

when a nucleus undergoes alpha decay the mass number decreases by 4 (top) and the atomic number decreases by 2 (bottom)

Question 15

what is beta decay

Answer 15

when this occurs the mass number is unchanged (top) the atomic number increases by 1

Question 16

what is gamma decay

Answer 16

this can occur after either alpha or beta decay

gamma decay is responsible for removing left over energy from within the nuclei

Question 17

what is nuclear fission

Answer 17

the breaking up of a large nucleus into two smaller nuclei

Question 18

what are the two types of fission

Answer 18

spontaneous - a nucleus breaks down without any external influence (happens with heavy unstable man made isotopes)
induced fission- a nucleus breaks down after being bombarded with a neutron, this takes place in a reactor

Question 19

what is nuclear fusion

Answer 19

the joining of two smaller nuclei to form a large nucleus
fusion powered stars is the method by which all of the elements in the universe were formed.
this happens all the time in stars at very high pressures and temperatures these conditions overcome repulsive forces between the nuclei and force them together

Question 20

how to calculate the energy released is fission and fusion reactions

Answer 20

e=mc2
total the lhs mass
total the rhs mass 
subtract lhs from rhs to get the mass lost 
sub into e=mc2 
DO NOT ROUND TILL THE END

Question 21

what is a chain reaction

Answer 21

when fission takes place neutons are released, these neutrons can collide with other nuclei and cause further fission reactions to take place and can go on forever.