Nuclear Flashcards
What particles are found in a Nucleus?
Protons and Neutrons
Describe the structure of an atom based on Rutherford Findings
A heavy nucleus made of positive protons and neutral netrons, with negative electrons orbiting. Most of the Atom is empty space.
Compare mass and charge of protons and electrons
Proton charge +1, Electron charge -1. Proton almost 2000 times heavier than electron
What were the three findings of Rutherford’s experiment
Alpha particles fired at thin gold sheet. Most Alpha Particles went through unaffected. A few deflected, and very few bounced straight back
What are the three types of radioactive emiossions. Describe them
Alpha: 2 p and 2 n (nucleus of Helium). Beta: fast moving electrons. Gamma: High frequency waves of energy
What does Ionising mean?
When a particle collides with an atom, and knocks or pushes out some of the electrons.
Why is Ionisation dangerous?
It can destroy cells, or mutate them and turn them cancerous
Which Radioactive emission is most dangerous where?
Alpha inside the body: Highly Ionising. Gamma outside the body: Non Ionising but very penetrative
What blocks each type of radioactive emission?
Alpha : thin paper or a few cm of air. Beta: thin Aluminium foil. Gamma: Many cm of Lead, or several m of Concrete
Main uses of Alph Radiation
Smoke detectors (can you describe how it works??)
Main uses of Beta Radiation
Checking thickness of paper in Industry, Tracers (How does that work??)
Main uses of Gamma Radiation
Killing Cancer cells. Tracers in the human body. Sterilising surgical equipment.
What do we mean by half life?
The time taken for half the radioactive nucleii in a material to decay
How many half lives would it take for a radioactive sample to decay from 1000 counts per minute to 125 counts per minutes
3 (1000 to 500, 500 to 250, 250 to 125)
Describe nuclear Fission
A slow mobing neutron is absorbed by a Uranium or Plutonium nucleus, The nucleus splits into two smaller nuclei, 3 more neutrons, and energy
