Matter and Radiation - 1

Question 1

What does the word nucleon include?

Answer 1

protons and neutrons - nucleus

Question 2

What is the charge of the nucleus

Answer 2

positive depending on the number of protons

Question 3

what type of microscope do you need to see atoms?

Answer 3

electron microscope

Question 4

What did Rutherfords alpha scattering experiment show?

Answer 4

positively charged nucleus and elections surrounding nucleus.

Question 5

What holds electrons in the atom?

Answer 5

electrostatic force

Question 6

What two sub atomic particles have similar masses?

Answer 6

protons and neutrons

Question 7

what is an isotope?

Answer 7

an atom of an element with the same number of protons but a different number of neutrons.

Question 8

what is the nucleon number?

Answer 8

number of protons and neutrons

Question 9

what is the mass number?

Answer 9

same as the nucleon number

Question 10

what is specific charge?

Answer 10

charge / mass

Question 11

what holds stable nuclei together in a stable nucleus?

Answer 11

strong nuclear force

Question 12

what does the strong nuclear force overcome?

Answer 12

electrostatic force between protons

Question 13

what is the range of the strong nuclear force when its attractive?

Answer 13

0.5 - 4 fm ( 1 fm = 1x^-15 m)

Question 14

what range is the strong nuclear force repulsive?

Answer 14

0-0.5 fm

Question 15

what is alpha radiation

Answer 15

2 protons 2 neutrons

Question 16

what type of radiation is detected in PET scanners?

Answer 16

gamma radiation

Question 17

what happens when a corresponding particle and antiparticle collide?

Answer 17

they anhililate

Question 18

what is an antiparticle?

Answer 18

a particle with equal and opposite charge and equal rest mass

Question 19

what’s the difference between pair production and annihilation?

Answer 19

pair production is where photons create a particle and antiparticle, while annihilation is where a particle and corresponding antiparticle collide and create two photons.

Question 20

what are the products of annihilation?

Answer 20

radiation energy - two photons

Question 21

what’s the minimum energy of a photon in pair production?

Answer 21

hf min = E0

Question 22

what’s the minimum energy of a photon in a pair production?

Answer 22

hf min = 2E0

Question 23

what did Feynman say was the reason for electromagnetic particles?

Answer 23

virtual photons (y)

Question 24

what is the virtual photon represented by in a Feynman diagram?

Answer 24

a wave

Question 25

describe the weak nuclear reaction with a Feynman diagram

Answer 25

neutrino + neutron = proton + beta minus including w- boson | antineutrino +neutron = proton + beta plus. including w+ boson

Question 26

describe beta - decay with a Feynman diagram?

Answer 26

neutron = antineutrino + w- boson + beta minus + proton

Question 27

describe beta + decay with a Feynman diagram?

Answer 27

proton = neutrino + neutron + beta+ + w+ boson

Question 28

describe electron capture on a Feynman diagram?

Answer 28

proton + e- = neutron + neutrino

Question 29

name two force carriers

Answer 29

photons and w bosons

Question 30

describe the interaction that is responsible for keeping protons and neutrons together in a stable nucleus

Answer 30

``` strong interaction repels 0-0.5fm attracts 0.5-3 fm keeps nuclei at an equilibrium distance from each other short distance and acts on hadrons ```

Question 31

how is baryon number conserved in alpha decay?

Answer 31

the number of protons and neutrons stays the same, therefore baryon number is conserved

Question 32

how is baryon number conserved in beta decay?

Answer 32

a neutron turns into a proton and so baryon number stays the same, and an electron has a baryon number pf 0 and so no change

Question 33

if an atom gains an electron what charge does it have?

Answer 33

negative

Question 34

if an atom loses an electron what charge does it have

Answer 34

positive

Question 35

to create a new element what must happen?

Answer 35

the atom most gain or lose a proton

Question 36

at what range does the electrostatic force work?

Answer 36

its long range and follows the inverse square law

Question 37

how do you identify a strange particle?

Answer 37

it has a strange quark + usually decays via the weak interaction