P6 - Radioactive Materials Flashcards
(43 cards)
Atom
The smallest part of the element it makes up
What was the 1909 Rutherford-Geiger-Marsden Alpha Scattering Experiment? (2)
An experiment to prove the structure of an atom, during which alpha particles were fired at gold foil
What were the three observations recorder during the 1909 Rutherford-Geiger-Marsden Alpha Scattering Experiment?
- Most alpha particles passed straight through the gold foil undeviated
- A few particles were deflected through small angles
- Even fewer bounced straight back from the foil
What were the three conclusions of the 1909 Rutherford-Geiger-Marsden Alpha Scattering Experiment?
- The atom is mostly empty space since most particles went straight through
- The mass and charge of an atom is concentrated in a small area in he centre of the atom (nucleus)
- The nucleus was positive because the positive alpha particles were repelled
Isotopes
Atoms of the same element with the same number of protons but differing numbers of neutrons
Name the three isotopes of Hydrogen:
Hydrogen = 1 neutron Deuterium = 2 neutron Tritium = 3 neutron
What does ionising radiation do to atoms?
It knocks electrons off and turns atoms into positive ions
Background radiation
Low level ionising radiation that is all around us
What are the 6 main sources of background radiation?
- Gamma rays from the ground and buildings
- Medical Sources
- Radon gas from the ground
- Nuclear power/ weapons testing
- Food and Drink
- Cosmic rays
The amount of radiation emitted by a radioactive source depends on…
The amount of radioactive material present
What are the three types of ionising radiation?
Alpha, Beta and Gamma
What are the properties of alpha radiation? (4) (structure, charge, ionisation, penetration)
- Two protons, two neutrons like a helium nucleus
- 2+ charge
- Highly ionising
- Low penetration
What are the properties of beta radiation? (4) (structure, charge, ionisation, penetration)
- Fast moving election
- 1- Charge
- Medium ionising power
- Medium Penetration
What are the properties of gamma radiation? (3) (structure, ionisation, penetration)
- High frequency electromagnetic wave
- Low ionising power
- High penetration
What materials can be used to absorb each type of ionising radiation? (3)
Alpha particles - Paper
Beta particles - Thin sheet of aluminium
Gamma rays - Thick block of lead/ concrete
How does high intensity radiation affect living cells? (2)
It can kill living cells and cause tissue damage leading to radiation sickness or cause cells to become sterile
How does low intensity radiation affect living cells?
It can affect the genetic makeup of a cells, causing mutations that could lead to cancer
Which type of radiation is dangerous inside the body and why?
Alpha radiation is the most dangerous because it is easily absorbed by cells
Which type of radiation is dangerous outside the body and why?
Beta and Gamma radiation because they can penetrate the body
What is the unit of Radiation absorbed?
A sievert (Sv)
What 4 elements are the most highly susceptible to ionising radiation in the body?
Oxygen, Hydrogen, Nitrogen and Carbon
Radioactive decay
When the radioactivity of of a material decreases over time as the amount of radioactive nuclei decreases
What happens in an atom during beta emission?
A neutron becomes a proton
What does emitting a gamma ray do to an atom?
Release energy only
