Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics > 1) Radioactivity > Flashcards

1) Radioactivity Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

what did J.J. Thompson discover?

A
  • electrons can be removed from an atom

- so an atom must have smaller parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the plum pudding model and who discovered it?

A
  • Rutherford and Marsden

- firing alpha particles at thin gold foil and seeing how many went through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the current model of the atom?

A
  • positively charged nucleus

- negatively charged electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the relative mass of a proton?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the relative mass of a neutron?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the relative mass of an electron?

A

0.0005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the relative charge of a proton?

A

+1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the relative charge of a neutron?

A

0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the relative change of an electron?

A

-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the charge of the nucleus of each element and how if it different to isotopes?

A
  • positive charge in the nucleus of each element

- isotopes differ in mass by having different numbers of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in an atom the number of protons is equal…

A

to the number of electrons so atoms are neutral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when are electrons able to change orbit?

A

when there is absorption or emission of electromagnetic radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens if an atom looses an outer electon?

A

become positive ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how is beta minus, positron, gamma rays and neutron radiation emitted?

A

emitted from unstable nuclei in a random process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are better minus, positron and gamma rays?

A

ionising radiations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is meant by background radiation?

A

-low level radiation that surrounds us all the time

17
Q

where does background radiation come from?

A
  • human activity, nuclear waste
  • space
  • naturally, air, foods, building materials
18
Q

how can we monitor radiation and stop irritation?

A
  • medical people wear photographic film badges to monitor exposure
  • keep things in lead boxes
19
Q

what is an alpha particle equivalent to?

A

helium nucleus

20
Q

what is a beta particle?

A

an electron emitted form the nucleus

21
Q

what is a gamma ray?

A

electromagnetic radiation

22
Q

how do alpha particles behave in terms of penetrations and ionising?

A
  • dont penetrate far, quickly absorbed by materials

- strongly ionising because of size

23
Q

how do beta particles behave in terms of penetrations and ionising?

A
  • moderately ionising
  • beta- has a range of a few meters in air and abroad by aluminium
  • beta+ have small range
24
Q

how do gamma particles behave in terms of penetrations and ionising?

A
  • penetrate far into materials with being stopped

- weakly ionising

25
Q

what happens in the process of b- decay?

A

a neutron becomes a proton and an electron

26
Q

what happens in the process of B+ decay?

A

a proton becomes a neutron and a electron

27
Q

what happens to nuclei which has often undergone radioactive decay?

A

they undergo nuclear rearrangement with a loss of energy as gamma radiation

28
Q

how does the activity of a radioactive source decrease over time?

A
  • as it decays a radioactive nucleus disappears
  • activity decreases
  • never reaches 0
  • half life
29
Q

what is the unit of activity on a radioactive isotopes?

A

becquerel Bq

30
Q

what is the half life?

A

time taken for half the undecided nuclei to decay or the activity of a source to decay by a half

31
Q

can it be predicted when a particular nucleus decays?

A
  • not be predicted

- half life enables large number of nuclei to be predicted

32
Q

HALF LIFE EQUATIONS

A

HALF LIFE EQUATIONS

33
Q

what are the dangers of ionising radiation?

A
  • tissue damage

- mutations, cancer

34
Q

what is the safety done to protect people from radiation?

A
  • medical, limiting doctors and patients by shielding

- limiting doses for patients as it kills too many cells

35
Q

what is contamination?

A
  • radioactive partiales on objects

- may decay leasing radiation

36
Q

what are irradiation effects?

A

-exposure to radiation

Physics (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions