Atomic Structure and Radiation Flashcards
Explain alpha radiation
It is the least penetrating as they are big particles yet the most ionising. it consists of just 2 protons and 2 neutrons giving it a 2+ charge. It is a helium atom
Explain beta radiation
A neutron changes into a proton and electron. They have a charge of 1- and penetrate moderatley and the same is with ionisation.
Explain gamma radiation
They are electromagnetic waves produced from the nucleus. They travel long distances and are the most penetrating but weakly ionising
With Uranium
Explain the alpha decay equation
Alpha particles are made up of a helium nucleus. This alpha decay allows an atom to change into a new element.
238 92 U -> 234 90 Th + 4 2 He
With Carbon
Explain the beta decay equation
Beta origantes from an unstable isotope allowing the neutron to change into a proton and electron. This changes the element and the electron is released
14 6 C -> 14 7 N + 0 -1 e
e is electron
What is the definition of half life
The time taken for all the radioactive nuclei in a sample to halve
How do you calculate half life on a graph
You go along the y axis with bequerels. Find half of the starting activity. Then go along to the time that correlates and thats half life. Do it again with another number to make sure.
The half life of the source is 40 hrs
There are 3,000,000 raidoactive nuclei in a sample how many will there be after 5 days
5dx24hrs=120hrs/40hrs= 3 Half lives
3,000,000/2 three times= 375,000
What is irradiation
Any object that has been exposed to radiation
What is contamination
When unwanted radioactive particles get in contact with other materials.
How could someone protect themselves from radiation
By keeping the radioactive substance out the container for a limited time. And by holding the substance with tongs and not hands
What is nuclear fission
The splitting up of large unstable nuclei into small stable nuclei. Which releases lots of energy.
Step by Step use Uranium as an example
How does fission happen and explain the chain reaction
A neutron collides into a unstable nucleus like Uranium. This releases three neutrons and the nuclei splits in two. These neutrons also hit other Uranium nuclei which leads to more neutrons being fired at more Uranium nuclei.
What is a use of a controlled nuclear fission and uncontrolled
A use of controlled nuclear fission is by nucelar reactors to get energy.
An uncontrolled use is with nuclear bombs.
What radiation is released from fission
Gamma or Y
