P4 Atomic Structure & Radioactivity Flashcards
What are the 3 different types of radiation
Alpha
Beta
Gamma
List the types of radiation in increasing terms of ionisation
Most ^ Alpha
|Beta
Least |Gamma
Why is alpha radiation the most ionising
It has the most mass - higher chance of colliding with an electron
It has the highest charge - higher chance of attracting an electron
Order the 3 types of radiation in how far they can travel in air
Most ^ Gamma
| Beta
Least| Alpha
Why is ionising radiation dangerous to humans
It can destroy DNA causing cancer
What is the approximate radius of an atom
1*10^-10
What is activity
The number of unstable atoms that decay per second in a radioactive source
What is count rate
The number of counts per second detected by a Geiger counter
What is the units of count rate
Becquerels ( Bq )
What is a half life
Average time taken for the number of the isotopes (or mass) in a sample to half
What is the difference between irradiated and contaminated
Substances that have been irritated do not become radioactive
What is ionisation
The process of which atoms become charged
Who created the solid sphere model of the atom
Dalton
Who created the plum pudding model of the atom
Thompson
Who created the nuclear model of the atom
Rutherford
What experiment did Rutherford conduct to create the nuclear model
Firing alpha particle at gold leaf
Who created the planetary model of the atom
Bohr
How is alpha radiation used
Smoke detectors
How is beta radiation used in industry
Paper thickness
How is gamma radiation used in industry
Irradiating food to make it free of bacteria
What are 4 ways radiation can be used in medicine
PET scans ( positron emission tomography )
Tracers
Radioactive implants
Radiotherapy
How does a pet scan work
Uses a tracer to show metabolic activity
