sp6 radioactivity (paper 1) Flashcards
define radiation
emission of energy as electromagnetix waves or as a moving subatomic particles, from the nuclei of atoms
state the different types of radiation
- alpha
- beta +
- beta -
- gamma
- neutron
composition of alpha radiation and the charge
- 2 protons and 2 neutrons
- +2
composition of beta - radiation and the charge
- 1 electron
- -1
composition of beta + radiation and the charge
- 1 positron
- +1
composition of gamma radiation and the charge
- a high frequency with electromagnetic radiation
- 0
what are alpha particles stopped by
- paper / foil
what are beta + particles stopped by
- stopped by aliminium
what are beta - particles stopped by
- stopped by aliminium
what are gamma particles stopped by
- stopped by thick led
what are neutron particles stopped by
- stopped by water / concrete
symbol of alpha radiation
- a
- 4/2 He
symbol of beta - radiation
- B -
- 0/-1 e
symbol of beta + / positron radiation
- B +
- 0/1 e
symbol of neutron radiation
- n
why does gamma radiation have no equation
because gamma radiation has no mass and no electric charge
what is the half life of a radioactive element
- the time it take half of the atoms in a sample to decay
- each element has its own decay rate and it is constant
state how fusion in stars occur
- nuclear fusion is the energy source for stars
- when hydrogen nuclei fuse together in a star, by the process of nuclear fusion helium nuclei are formed
- a neutron and energy are also released from this reaction
(in larger stars, this process can repeat where helium nuclei continue to fuse, forming heavier elements)
define nuclear fusion
2 small nuclei will be joined together to form a larger nucleus
what is the end product of nuclear fusion
- nucleus is heavy
- a lot of energy is produced
- some mass is lost, and it turns into energy (released as radiation)
conditions for nuclear fusion
- high pressure (to overcome electrostatic repulsion)
- high tempurature (between the positively charged nuclei of each isotope, energy is found to overcome the electrostatic repulsion)
define nuclear fission
splitting a large, unstable nucleus into 2 smaller particles
describe the process of nuclear fission
- unstable nucleus absorbs a neutron
- nucleus splits into two#
- neutrons and gamma rays are emitted
state the products of nuclear fission
- the fission proucts have kinetic energy, which allows them to move away from the original action site
- gamma rays carry excess energy, which allows them to move away from the original action site
- neutrons can start a chain reaction (as neutrons with kinetic energy is released, allowing it to be absorbed by another unstable nucleus)