Matter and radiation

Question 1

nucleon

Answer 1

-word used for proton or neutron in nucleus

Question 2

how are electrons held in the atom

Answer 2

electrostatic force between positive nucleus and negative electrons

Question 3

charge of proton and electron

Answer 3

• proton= +1.6x10^-19

- electron= -1.6x10^-19

Question 4

mass of neutron and proton

Answer 4

-1.67x10^-27

Question 5

mass of electron

Answer 5

• 9.11x10^-31

- mass is so small we do not include it in calculations

Question 6

isotope

Answer 6

-atoms with same no of protons and diff no of neutrons

Question 7

nucleon number

Answer 7

-mass number/ total no of protons and neutrons in nucleus

Question 8

nuclide

Answer 8

type of nucleus

Question 9

Specific charge equation

Answer 9

SC=Charge, divided by mass

Question 10

role of strong nuclear force

Answer 10

overcomes the electrostatic force of repulsion between 2 protons in nucleus and keeps protons and neutrons together

Question 11

range of strong nuclear force + es force

Answer 11

• strong nuclear =3-4 fm (femtometres)

- es = infinite range although decreases when range increases

Question 12

how does force of strong nuclear change with range

Answer 12

• attractive force from 3-4 fm down to 0.5.

- when smaller, changes to a repulsive force to prevent protons and neutrons being pushed into each other

Question 13

what happens to an unstable nucleus that emits alpha radiation

Answer 13

• nucleon no decreases by 4
• atomic no decreases by 2
• hence becomes a diff element

Question 14

beta minus decay (learn diagram)

Answer 14

• neutron turns into proton + beta minus + antineutrino
• charge, baryon no and lepton no must be conserved
• atomic no increases by 1

Question 15

beta plus decay/positron (learn diagram)

Answer 15

• proton> neutron + beta plus + neutrino

- atomic no decrease by 1

Question 16

when is gamma radiation emitted

Answer 16

-when a nucleus has too much energy, followed by alpha or beta emission

Question 17

what does an em wave consist of

Answer 17

• an electric and magnetic wave travelling at right angles to each other and direction at which theyre travelling
• in phase with each other

Question 18

when is an em wave emitted

Answer 18

-when a charged particle loses energy

Question 19

photon + equation for photon energy

Answer 19

• small packet of em waves
• E=hf
• f= frequency
• h = planck constant
• massless= can only travel at speed of light

Question 20

power of laser beam

Answer 20

• energy per second transferred by the protons

- power of beam = nhf

Question 21

1 electron volt=

Answer 21

the energy transferred when an electron is moved through a potential difference of 1 volt

Question 22

annihilation

Answer 22

• when a particle and a corresponding antiparticle meet and their mass is converted into radiation energy]
• 2 photons are produced

Question 23

pair production

Answer 23

-photon creates a particle and a corresponding antiparticle and vanishes

Question 24

particle repulsion

Answer 24

• caused by exchange of virtual photons= gauge bosons

- like throwing a ball, person will move back when catching it

Question 25

particle attraction

Answer 25

- gauge bosons | - like a boomerang, when caught move closer together

Question 26

role of weak nuclear force

Answer 26

-causes proton to turn into neutron in b+ and vice versa

Question 27

w bosons

Answer 27

- w-, for neutron and neutrino interaction - w+ for proton and antineutrino interaction - if no neutrino or antineutrino is present, w- decays into b- and antineutrino and w+ decays into b+ and neutrino

Question 28

electron capture

Answer 28

- a proton in a proton rich nucleus turns into a neutron as a result of interacting through the weak interaction with an inner shell electron - w+ boson changes into a neutrino