radiation

isotope

An isotope is an atom of the same element that has the same number of protons but a different number of neutrons.

Example: Carbon

• Carbon-12: 6 protons, 6 neutrons.

• Carbon-14: 6 protons, 8 neutrons.

proton stays because protons cant change

radioactive isotope

A radioactive isotope is an isotope with an unstable nucleus that releases radiation as it breaks down to become more stable.

Example: Carbon-14 is a radioactive isotope.

Exam definition to remember:
An isotope with an unstable nucleus that emits radiation as it decays

what stops gamma

cm of lead or concetre

whats stops beta

aluminmun foil

what stops alpha

paper

What is ionising radiation?

Ionising radiation is radiation with enough energy to remove electrons from atoms, turning them into charged particles called ions.

amplitude

The maximum displacement of a wave from its resting position. (hight above midpoint)

wavelength

difference of 2 sets of crests/throughs

frequency

how many waves per second

rule

f= wave number/time= 10/5=2hz

types of atoms

-proton

-neutron

-electron

What is alpha decay?

When an unstable nucleus releases an alpha particle (2 protons and 2 neutrons), reducing its atomic number by 2 and mass number by 4.

what is beta decay

When a neutron changes into a proton and releases a beta particle (electron), increasing the atomic number by 1 while the mass number stays the same.

what is gamma decay

just energy

half life

The time taken for half of the radioactive atoms in a sample to decay.

carbon 14 dating

A method scientists use to find out how old once-living things (such as bones and fossils) are. They measure how much carbon-14 remains, because it slowly decays over time.

how to find mass number

proton+ neutron

wave equation

Back:

• Wave speed: v=fxy

• Frequency: y=v/f

• Wavelength: f=v/y

Where:

• v= wave speed (m/s)

• f = frequency (Hz)

• y = wavelength (m)

non ionizing radiation

Radiation that does not have enough energy to remove electrons from atoms and create ions.

Examples: Radio waves, microwaves, infrared and visible light.

electromagnetic spectrum inorder from lowest to highest frequency

1. Radio waves

2. Microwaves

3. Infrared

4. Visible light

5. Ultraviolet (UV)

6. X-rays

7. Gamma rays

how far can it travel beta, alpha and gamma

alpha: 10cm

beta: few metres

gamma: very far (compared to others)

is alpha, beta and gamma a danger to humans

alpha: cant get through skin but can be dangerous if ingested

beta: skin can burn and dangerous if ingested or inhaled

gamma: very dangerous damge internal organs

what is radiation

Energy that travels through space or matter as waves or particles. It can come from natural or man-made sources.