P7 Flashcards
What is Nuclear Radiation?
When the nucleus of an atom emits radiation because it’s unstable
This would be because it has : too many protons, too many neutrons or its too large
What types of radiation were first discovered and by who?
Rutherford discovered :
- Alpha Radiation
- Beta Radiation
Who discovered Gamma Radiation
It was discovered after Alpha and Beta by scientists
How were radioactive materials discovered?
Becquerel -> Curie’s -> Rutherford
Describe the Plum Pudding model
- Atoms are spheres of positive charge
- Electrons are dotted around inside
Describe Rutherford’s scattering experiement
1) Alpha particles were aimed at gild foil
2) It was expected that they’d to travel straight through the gold but some bounced back and deflected
What was concluded after Rutherford’s scatterinh experiment?
There’s a nucleus in the centre of the atom that is
- positvely charged
- where most mass is located
- much smaller than the atom
Describe Alpha Particles
- Made of 2 protons amd neutrons
- Have a charge of 2+
- Mass of 4
- The same as a helium nucleus
- No electrons
What does a Alpha Particle look like ( numbers ) ?
4
a
2
What is are Beta Particles?
An electron creared and emmited by a nucleus which has too many neutrons compared to protons
What does a Beta Particle look like ( numbers ) ?
0
B
-1
Mass doesn’t change but atomic number changes ( add 1 )
What is an Gamma decay?
Gamma rafiation is emitted by some unstable nuclei after an alpha or beta particle has been emitted
Gamma has no effect on atomic number or mass number
How do Alpha particles deflect?
They deflect in 1 direction in a magnetic field, but not as much as beta due to their size
How do Beta particles deflect?
They deflect in the other direction and the faster the particle is travelling, the more momentum it has so deflects less
How to Gamma Rays deflect?
They’re undeflected as it’s unchanged
