Unit 2 - Radioactivity Flashcards
What is an isotope and what does it contain?
Isotopes are atoms of an element with the normal number of protons and electrons, but different numbers of neutrons.
Isotopes have the same *atomic *number, but different mass numbers.
What is the symbol for Alpha?
What is the symbol for Beta?
What is the symbol for Gamma?
What is the nature of Alpha?
2 protons, 2 neutrons
What is the nature of Beta?
Electron
What is the nature of gamma?
Electromagetic wave
What are Alpha, Beta and Gamma’s charges?
Alpha ** 2+**
Beta -1
Gamma 0
What is the mass of Alpha?
Large
What is the mass of Beta and Gamma?
Tiny
What ionising power does Alpha have?
Huge / Very big
What ionising power does Beta have?
Small
What ionising powerd does Gamma have?
Tiny
What is the penetrating power of Alpha?
Paper / a few cm of air
What is the penetrating power of Beta?
A few mm of Aluminium
What s the penetration power of Gamma?
Concrete / several cm of lead
What is the half life of a radioactiv isotope?
the time taken for;
- The **number of radioactive atoms **
&
- The count rate (no of counts per second)
To half
Isotope
Atoms with the same number of protons but different number of neutrons
Radioactive
A raditactive atom is one that emits radiation from its nucleus
Radiation
Aplha, Beta and Gamma
Definition of Alpha
A helium nucleus
Definition of Beta
An electron released from a nucleus
Definition of Gamma
An electromgnetic wave/ray
Half life
The time it takes for an elements count rate to half
Ion
An atom that has lost or gaines electrons
Ionising
It can create ions
What are the hazards of nuclead radiation?
- Can ionise atoms in our bodies
- This can stop/change chemical reactions in our cells
- Damage to DNA may cause mutations
Symptoms of a low dose of radiation?
Nausea and sickness
Symptoms of a moderate dose of radiation?
Skin damage and hair loss
Symptoms of a high does of radiation?
Cancers, sterility, death
Ways to minimise dosage of radiation?
- Wear a monitor
- Reduce exposure
- Shield (lead apron, concrete & thick glass)
- Remote control handling
How is radiation used to kill cancer in the brain?
Gamma ray treatment
- Lots of low dose beams to minimis the damage of healthy tissure
- Aims to kill all the cellls but leave the surrounding tissure unharmed
deflection in a magnetic/electric field: Gamma?
Never deflected because it has no charge
Deflection in a magnetic/electric field: Alpha?
Isn’t deflected much because;
- It has a (positive) charge
- It has a lot of mass (to heavy to be moved much by force)
Deflection in a magnetic/electric field: Beta?
Deflected because;
- Has a (negative) charge
- Opposie direction to alpha because it has less mass (the force moves it more because its lighter)
Fission
Nuclear fission is the splitting of an atomic nucleus, resulting in the release of large amounts of energy
Uncontrolled Chain reaction?
Eg bomb
Controlled Chain Rection
eg nuclear power station
Fusion
The joining together of 2 small nuclei to form a nucleus of a larger element, it releases a lot of energy
Life cycle of stars?
Average star - about the same size as the sun
