Brainscape's Knowledge GenomeTM

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


See full index

GCSE physics > P7 > Flashcards

P7 Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards GCSE Religious Studies - Edexcel Route A flashcards AP® Physics flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Geography - AQA flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

Where in the atom does nuclear radiation come from

A

The nucleus

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

What is ionising radiation

A

Radiation that changes an atom into an ion

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

What can ionising radiation cause

A

Cancer- mutates dna and kills cells

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

What is radiation

A

The particles or waves being emmited by radioactive substances

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

In a radioactive atom, why are particles or waves emmited

A

The nucleus is unstable and so it emits particles or waves to form a more stable atom. This process is called radioactivity or radioactive decay

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

What is nuclear fission

A

Big nuclei being split into 2 or more daughter nuclei

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

What is nuclear fusion

A

2 smaller atoms joining together - making a bigger atom / nucleus

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

When was daltons’s model of the atom

A

1808

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

What did dalton come up with

A

All matter is made up of tiny spherical atoms, atoms can’t be broken into smaller parts, atoms of particular elements are identical and differ from those of other elements

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

When was JJ thompsons plum pudding model discovered

A

1904

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

What did jj thompson come up with

A

He knew there were electrons, he knew there was no electric charge so he came up with a sphere of positive charge with electrons evenly distributed

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

When was rutherfords nuclear model of the atom discivered

A

1911

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

3 of rutherfords observations

A
  • Most alpha particles went straight through meaning most of the atom is empty space
  • some particles are deflected meaning the nucleus is very small and in the centre
  • very few particles are repelled back meaning the nucleus is positively charged
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does an alpha particle contain

A

2 protons and 2 neutrons

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

When was bohr’s plantenary model of the atom discovered

A

1914

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

What did bohr discover

A

The electrons are aranged in shells which orbit the nucleus. They can move between shells by emitting or absorbing electromagnetic radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

3 reasons as to why some atoms are radioactive

A
  • nucleus is unstable
  • the nucleus has too many neutrons or not enough
  • nucleus is too big and wants to break up
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a radioisotope

A

The nucleus of isotope is unsavke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is activity?

A

The number of unstable nuclei that decay every second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is Count-rate?

A

The number of decays recorded each second by a detector

21
Q

What is half-life?

A

The time that it takes half the atom in a sample to decay

22
Q

What process is radioactive decay?

A

Spontaneous (can’t be controlled and not affected by temperature)

23
Q

How is alpha radiation stopped?

A

By paper

24
Q

How is beta radiation stopped?

A

A sheet of aluminium a few metres thick

25
Q

How are gamma rays stopped?

A

Thick walls of concrete or lead

26
Q

Why was rutherfords model accepted?

A

-agreed exactly with the measurements geiger and marsden made in their experiements
-explained radioactivity in terms of changes that happen to an unstable nuclei when emmiting radiation
-predicited existence of neutrons

27
Q

Problems with the plum pudding model:

A

Could not explain why some alpha particles were scattered through large angles

28
Q

Radioactive decay

A

An unstable nucleus becoming more stable by emitting alpha or beta particles

29
Q

Why are most nuclei stable?

A

Because the protons and neutrons inside a nucleus are held together by a string nuclear force

30
Q

Irridated

A

When an object is exposed to ionising radiation, but does not hecome radioactive

31
Q

Radioactive contamination

A

Unwanted presence of materials containing radioactive atoms on other materials

32
Q

What may cause ionisation?

A

X-rays, fast moving protons and neutrons

33
Q

How do workers who use ionising radiation reduce their exposure?

A

-keep as far away as possible from the source
-spending little time in at-risk areas
-sheilding themselves by staying behind thick concrete barriers

34
Q

Example of radiation in use:

A

Smoke alarms (contain the radioactive isotope that sends out alpha particles in a circuit)

35
Q

Current model of the atom:

A

-radius of atom is 1x10^-10
-electrons in energy levels move within the atom
-if they gain energy by absorbing EM radiation, they move to a higher energy level

36
Q

What do unstable isotopes do to other elements?

A

They tend to decay into other elements and give out radiation as they try to become more stable (radioactive decay)

37
Q

What does ionising radiation do to electrons?

A

It knocks them off atoms, creating positive ions. The ionising power of a radiation source is how easily it can do this

38
Q

Nuclear equations:

A

Atom before decay ➡️ atom after decay + radiation emitted

39
Q

Risks of ionising radiation:

A

It can enter living cells, damage them or kill them

40
Q

Irradiation

A

Exposure to radiation

41
Q

How to control irriadation:

A

-The source may be in a different room and remote control arms are used to handle it
-keeping sources in lead-lined boxes
–standing behind barriers

42
Q

How is something contaminated?

A

If unwanted radioactive atoms get onto, or into an object

43
Q

Example of contamination:

A

If you touch a radioactive source without wearing gloves

44
Q

How can you reduce contamination?

A

-Wear gloves and use tongs
-wear protective suits

45
Q

Why are alpha particles less dangerous?

A

It can’t penetrate skin

46
Q

How are alpha particles dangerous in the body?

A

-They damage very localised areas so contaminate them

47
Q

How are beta particles less damaging in the body?

A

Radiation is absorbed over a wider area and some passes out the body altogether

48
Q

How are gamma sources not dangerous in the body?

A

-they mostly pass straight out and have the lowest ionising power

GCSE physics (13 decks)

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