Radioactivity and Particles

Question 1

what is activity measured in?

Answer 1

radiation emitted per second
Bq- becquerel

Question 2

what is an isotope?

Answer 2

an atom with the same number of protons but different number of neutrons

Question 3

what is atomic number?

Answer 3

number of protons in a nucleus

Question 4

what is mass number?

Answer 4

number of nucleons (protons+neutrons) in a nucleus

Question 5

what is alpha, beta particles and gamma rays?

Answer 5

ionising radiation emitted from an unstable nuclei in a ransom process

Question 6

what is ionising radiation?

Answer 6

radiation that can ionise another atom (high energy)

Question 7

what are the dangers of ionising radiation?

Answer 7

could mutate the DNA inside the cells which could go on to causing cancer

Question 8

what is the nature and the relative charge of alpha particles?

Answer 8

2 protons + 2 neutrons
charge=+2

Question 9

what is the nature and relative charge of beta particles?

Answer 9

fast moving electron
charge=-1

Question 10

what is the nature and the relative charge of gamma rays?

Answer 10

electromagnetic wave
charge=0

Question 11

what is the penetrating power of alpha, beta and gamma?

Answer 11

alpha-low
beta-medium
gamma-high

Question 12

what is the ionising power of alpha, beta and gamma?

Answer 12

alpha-high
beta-medium
gamma-low

Question 13

what is an absorber for alpha?

Answer 13

thin paper

Question 14

what is an absorber for beta?

Answer 14

aluminium

Question 15

what is an absorber for gamma?

Answer 15

thick lead/ concrete

Question 16

what is ionising power?

Answer 16

This is ability of the radiation to cause another atom to gain or lose electrons. When this happens the radiation is absorbed

Question 17

what is penetrating power?

Answer 17

This is the ability of the radiation to travel through a material without being absorbed.

Question 18

what can detect ionising radiation?

Answer 18

Geiger Muller tube and the counter to record how many times the radiation was detected

Question 19

what can detect ionising radiation? 2

Answer 19

photographic plates

Question 20

what is background radiation?

Answer 20

radiation that is around us all the time

Question 21

what is background radiation made of?

Answer 21

-gas from the ground-50% radon gas
-food+drink
-cosmic rays
-building + the ground
-artificial sources (human technologies)

Question 22

what is half life?

Answer 22

the average time taken for half of unstable nuclei to decay

Question 23

what are the uses of radioactivity in industry and medicine?

Answer 23

smoke detectors
manufacture of aluminium foil
radioactive tracers
medical tracers
carbon dating

Question 24

what is contaminated?

Answer 24

radioactive source inside the object, this can decay and emit radiation

Question 25

what is irradiated?

Answer 25

radiation passes through it -when happens kills bacteria (sterilise)

Question 26

what are the dangers of ionising radiation?

Answer 26

mutations of living organisms cell+tissue damage problems with disposal of radioactive waste

Question 27

what is fission?

Answer 27

The nucleus is very large and unstable then it can undergo fission.This is where the nucleus split into two nuclei

Question 28

what elements does fission occur for?

Answer 28

uranium polonium

Question 29

describe the process of fission

Answer 29

-slow moving neutron which is absorbed by uranium-235, creating uranium-236 (very unstable) - the nucleus splits into 2 daughter nuclei and usually 2 or 3 neutrons and lots of energy

Question 30

what type of energy is released during fission?

Answer 30

the energy released as kinetic energy lots of kinetic energy then transfers to thermal energy

Question 31

what is a chain reaction?

Answer 31

where the product from one reaction go to become the reactant of the next reaction

Question 32

what is a runaway reaction?

Answer 32

when more and more product is created, causing more and more reactions per second, also producing more and more energy per second -it’s when more than1 neutron is released and each of there could cause more fission

Question 33

dangers of fission

Answer 33

-runaway reaction, as there is huge amounts of energy released that could cause and explosion -daughter nuclei that are released are unstable, which decay emitting alpha beta or gamma, which then damages cells and causes cancer

Question 34

what is the function of the control rods?

Answer 34

control the reaction by absorbing neutrons ( made of boron)

Question 35

what is the function of the moderator?

Answer 35

designed to slow down the neutrons which keeps the reaction going

Question 36

what is the function of the shielding around the nuclear reactor?

Answer 36

made of thick concrete which absorbs alpha and beta and reduces gamma to safe levels

Question 37

what is the function of the shielding around the nuclear reactor?

Answer 37

made of thick concrete which absorbs alpha and beta and reduces gamma to safe levels

Question 38

what is the function of a coolant?

Answer 38

water reduces the temperature of the reactor by transferring the heat away