Nuclear Fission And Fussion Flashcards
Electrons:
Have a charge of -1
Isotopes:
Isotopes are atoms of the same element with the same number of protons but different number of neutrons.
The atomic number will be the same but their mass number will change.
Protons:
Have a charge of +1
Neutrons:
Have a charge of 0
Ions:
If an atom gains or loses an electron, it becomes charged.
An atom with a charge is called an ion.
If an atom gains an electron it will be a negative ion.
If an atom loses an electron it will be a positive ion.
Ionising radiation:
Ionising radiation is radiation that has enough energy to cause atoms to lose electrons and so, become ions.
Three types of ionising radiation given out by radioactive materials:
Alpha particles
Beta particles
Gamma rays
Radioactive substances:
Have unstable nuclei that decay at random. When they decay they lose energy as ionising radiation. This makes their nuclei more stable.
Alpha particles:
2 protons and 2 neutrons - helium nucleus
mass of 4
+2 charge
very ionising
Can be blocked by a few cm of air or paper
Fast moving
Beta particles:
An electron
-1 charge
Negligible (no mass)
Less ionising than alpha
Can be blocked by a few mm of aluminium
Faster moving than alpha
Gamma rays:
An electromagnetic wave - not a particle
No charge
No mass
Less ionising than alpha and beta
Can be blocked by a few cm of lead
Most penetrating
Fastest moving
Radioactive materials:
When radioactive materials decay they make new elements.
If the mass number drops by 4 the unstable nucleus has emitted an alpha particle
In beta decay, a neutron breaks down into a proton and an electron.
Nuclear reactions:
Nuclear reactions release energy. For example:
- nuclear fission
- nuclear fusion
- radioactive decay
Nuclear fission:
- a large unstable nucleus
- absorbs a nucleus
- splits into two smaller daughter nuclei
- releases 2 or more neutrons
- releases lots of energy
Nuclear fusion:
- 2 small nuclei collide at a very high speed
- to form a larger nucleus
- releases a lot of energy
