Characteristics of the three types of emission Flashcards

1
Q

Radiation consists of ____________ emitted from the nucleus of an unstable atom.

A

high energy particles (or waves)

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

There are three (main) types of radiation:

A

alpha (α) particles, beta (β−) particles, or gamma (γ) rays

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

Radiation is emitted ___________

A

randomly
This means that, although we understand why some nuclei emit radiation, it is impossible to predict exactly when a nucleus will emit radiation

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

Alpha (α) particles are

A

high energy particles made up of 2 protons and 2 neutrons (the same as a helium nucleus).

They are usually emitted from nuclei that are too large

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

Beta (β−) particles are

A

high energy electrons emitted from the nucleus (even though the nucleus does not normally contain any electrons)
They are usually emitted by nuclei that have too many neutrons

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

Gamma (γ) rays are

A
  1. high energy electromagnetic waves
  2. They are emitted by nuclei that need to lose some energy
  3. If these particles hit other atoms, they can knock out electrons, ionising the atom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When radiation passes close to atoms, it can knock out electrons, _________ the atom

Ionisation can cause chemical changes in materials, and can damage or kill living cells

A

ionising

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

Charateristics summarized

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

As the range and penetration increase, but the ionisation ____________

A

decreases

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

Because they have opposite charges, alpha and beta particles are deflected in ___________ directions

Beta is deflected by more than alpha, because beta particles have a much ___________ mass

Gamma is not deflected because gamma rays have___________

A

opposite,smaller,no charge

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

Alpha and Beta particles can also be deflected by magnetic fields. To find the direction of the deflection, we use ____________.

A

Flemings Left hand rule

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

Alpha is by far the most _________of radiation

Alpha particles leave a dense trail of ions behind them, affecting virtually every atom they meet

Because of this they quickly lose their energy and so have a _________ range

Their short range makes them relatively harmless if handled carefully, but they have the potential to be extremely dangerous if the alpha emitter enters the body

A

ionising form, short,

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

Beta particles are __________ ionising

The particles create a less dense trail of ions than alpha, and consequently have a ______ range

They tend to be more dangerous than alpha because they are able to travel further and penetrate the skin, and yet are still ionising enough to cause significant damage

A

moderately, Longer

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

Gamma is the ________ ionising form of radiation (although it is still dangerous)

Because Gamma rays don’t produce as many ions as alpha or beta, they are more penetrating and have a __________ range

This can make them hazardous in large amounts

A

Least, longer

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

Radioactive decay

A

is a random and spontaneous process in which an unstable nucleus will disintegrate into a more stable configuration by the emission of alpha-particles (helium nuclei), beta-particles (electrons) and/or gamma radiation (short-wavelength electromagnetic waves).

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

radio-isotopes

A

Isotopes of an atom can be stable or unstable

A radioisotope has an unstable nucleus (too many neutrons and/or protons).

The unstable nuclei will try to become more stable by ejecting particles.

17
Q

Alpha Emission

A

An alpha particle consists of 2 protons and 2 neutrons
(It is emitted from large unstable nuclei)

When an alpha particle is emitted from a nucleus:

**The nucleus loses 2 protons:
The proton (atomic) number decreases by 2**
**The nucleus loses 4 particles (nucleons) in total:
The nucleon (mass) number decreases by 4**
18
Q

Beta Emission

A

A beta particle is a high energy electron emitted from the nucleus

  • It is emitted when a neutron in the nucleus suddenly changes into a proton – an electron is created in order to balance the positive charge of the proton*
  • *(Note: The electron is created at the moment of decay – it is not present in the neutron beforehand)**

When a beta particle is emitted from a nucleus:

The number of protons in the nucleus increases by 1:
The proton (atomic) number increases by 1

The total number of particles in the nucleus remains the same
The nucleon (mass) number doesn’t change

19
Q

Nuclear Fission

A

Usually large unstable nuclei break up gradually by the process of radioactive decay, but a small number (including Uranium-235, a naturally occurring isotope of Uranium) can break up in one big go – a process known as nuclear fission

20
Q

Nuclear Fusion

A

Nuclear fusion involves taking small nuclei (such as hydrogen) and colliding them together at high speed to form larger nuclei

21
Q

describe, with the aid of a block diagram, one type of fission reactor for use in a power station

A
22
Q

discuss theories of star formation and their energy production by fusion.

A
  1. (Nebula stage) Stars form when enough dust and gas clump together
  2. (protostar stage) This cloud of dust and gas starts to collapse due to its own gravitational forces. This gravitational force pulls the dust and gas together. As the gas falls together, it gets hot.
  3. (Fusion stage) A star forms when it is hot enough for nuclear reactions to start. This releases energy, and keeps the star hot.
23
Q

Radioactive emission is random and ____________.

A

Spontaneous

its is unaffected by any physical or chemical variable in the environment.

The radioactive process cannot be slowed down or speeded up by anything.