radiation

Question 1

what are the 3 types of particles that make up the atom

Answer 1

proton
neutron
electron

Question 2

what particles are found in the nucleus

Answer 2

protons and neutrons

Question 3

what orbits the nucleus

Answer 3

electrons

Question 4

charge and mass of a proton

Answer 4

+1
1

Question 5

charge and mass on neutron

Answer 5

0
1

Question 6

charge and mass of electron

Answer 6

-1
1/1836

Question 7

the nnumber of protons is called

Answer 7

the atomic number

Question 8

the number of protons and neutrons is called

Answer 8

the mass number

Question 9

what are nucleons

Answer 9

protons and neutrons

Question 10

what experiment did rutherford carry out

Answer 10

alpha scattering experiment

Question 11

what did rutherfords experiment show

Answer 11

that alpha particles ca pass through thin gold foil

Question 12

what did he do in this experiment

Answer 12

he fired aplha particles at thin golf foil. detectors were used to find how thr alpha particles were scattered by the gold atoms

Question 13

rutherfords explanation

Answer 13

rutherford showed that this could be explained if each atom has a tiny core or nucleus with a positive charge. a positive nucleus repels positive alpha particles so that they are scattered in different directions

Question 14

observation: most of the aplha particles went straight through the foil
explanation:

Answer 14

nucleus must be tiny (easy for alpha particles to miss)

Question 15

obervation: some particles were slightly deflected
explanation:

Answer 15

nucleus is charged

Question 16

obervation: a few particles “bounced” staight back

Answer 16

nucleus is positively charged and has much more mass than the alpha particle

Question 17

3 types of radiation

Answer 17

alpha
beta
gamma

Question 18

symbol equation for alpha particle

Answer 18

4 4
He or ∝
2 2

Question 19

symbol equation for beta particle

Answer 19

0 0
B or e
-1 -1

Question 20

where does rutherfords experiment happen

Answer 20

a vacuum

Question 21

when writing symbol equations it is important to remember that:

Answer 21

-mass numbers must balance
-atomic numbers must balance

Question 22

background radiation comes from:

Answer 22

rocks in the ground
bricks in building
nuclear waste from power stations and bomb tests
hospitals
outer space

Question 23

how do u measure background radiation

Answer 23

set up a G-M tube with no radioactive sources present
measure the count over a long period of time
divide the number of counts by the time to get the count rate in whichever unit is appropriate

Question 24

what is a corrected count rate

Answer 24

one which has the background rate suntracted from it

Question 25

what is meant by background radiation

Answer 25

radiation that is present in our enviroment all ready

Question 26

why is it vital that radiation doesnt get into r food chain

Answer 26

radioactivity is much more dangereous insude the body

Question 27

what does ionising radiation mean

Answer 27

radiation that can remove electrons from atomd in its path, so it has an ionising effect

Question 28

the range of radioactivity is ...

Answer 28

how far we could expect it to travel in a particular material before being stopped

Question 29

why is ionising radiation so dangerous

Answer 29

when a molecule of genes in living cells is ionised, the genetic material of a cell id damaged and may become cancerous

Question 30

name the 3 forms of nuclear radiation

Answer 30

alpha- ∝ beta- β gamma- γ

Question 31

dangers of radioactivity for living cells

Answer 31

when radiation collides with molecules in living cells it damages them. if the DNA in the nucleus of a cell is damaged, the cell may become cancerous. the cell then goes out of control, divides rapidly and causes serious health problems

Question 32

radiations is harmful because of its ...

Answer 32

penetrating nature, and its ability to ionise

Question 33

why is alpha radiation the most dangerous inside the body

Answer 33

because it is easily absorbed by cells

Question 34

what type of radiation is the most dangerous inside the body

Answer 34

alpha radiation

Question 35

what type of radiation is the least dangerous inside the body

Answer 35

beta and gamma

Question 36

why is beta and gamma radiation not as dangerous inside the body

Answer 36

because they are less likely to be absorbed by a cell and will usually just pass right through

Question 37

what type of radiation is the least dangerous outside the body

Answer 37

alpha

Question 38

what type of radiation is the most dangerous outside the body

Answer 38

beta and gamma

Question 39

why is alpha radiation not as dangerous outside the body

Answer 39

because it is unlikely to reach living cells inside the body

Question 40

why is beta and gamma radiation dangerous outside the body

Answer 40

because they can penetrate the skin and damage cells inside

Question 41

protection when handling radioactive sources

Answer 41

-wearing protective clothing -keeping the source as far away as possible by using tongs -limiting the exposure tome to as little as possible -keeping radioactive materials in lead lined containers

Question 42

uses of radioactivity

Answer 42

-in smoke detectors -for sterilising medical instruments -for killing cancer cells -for dating rocks and materials such as archaeological finds -in chemical tracers to help with medical diagnosis -for measuring the thickness of materials in, for example a paper factory

Question 43

decay is _____________________

Answer 43

random and spontaneous

Question 44

what does random mean

Answer 44

we can't predict when it will happen

Question 45

what does spontaneous mean

Answer 45

it happens on its own without are influence

Question 46

definitions of half life

Answer 46

1. the time for the number of undecayed nuclei to fall to half of its previous volume 2. the time for the activity to fall to half of its previous value

Question 47

what is nuclear fission

Answer 47

occurs when a large nucleus splits into two or more smaller nuclei

Question 48

where is nuclear fusion used

Answer 48

used in nuclear power stations to generate electricity

Question 49

summary of what happens in fission

Answer 49

uranium nucleus absorbs a neutron, then splits into two or more smaller nuclei, releasing energy, and several neutrons. these neutrons can then go on to cause other reactions and cause a chain reaction

Question 50

what is nuclear fusion

Answer 50

occurs when two light nuclei (hydrogen) join to form a new heavier nucleus (helium)

Question 51

where does nuclear fusion occur

Answer 51

in stars- it is the source of their energy

Question 52

what elements are used in fusion

Answer 52

isotopes of hydrogen

Question 53

name the 3 forms of hydrogen

Answer 53

hydrogen deuterium tritium

Question 54

write out a typical fusion reaction

Answer 54

2/1 H + 3/1 H → 4/2 He + 1/0 n + energy

Question 55

what conditions are required for fusion reactions to occur

Answer 55

extremely high temperatures and pressure

Question 56

why is fusion seen as a potential solution to solve the energy crisis

Answer 56

-the isotopes of hydrogen are widely available as the constituents of seawater -fusion does not emit carbon dioxide or other green house gases into the atmosphere - its major by-product is helium, which is inset and non-toxic

Question 57

how does fusion compare to fossil fuels and fission in terms of energy output

Answer 57

- fusion releases 4 million times more energy per kg than burning coal, oil or gas - fusion releases 4 times as much energy as nuclear fission reactions per kg