Seneca P4 Flashcards
What happens when an atom absorbs or emits electromagnetic radiation
Its electron arrangements change
What happens when atoms emit electromagnetic radiation
When atoms emit electromagnetic radiation, electrons can drop to a lower energy level, closer to the nucleus.
What happens when atoms absorb electromagnetic radiation
When atoms absorb electromagnetic radiation, electrons move to a higher energy level further away from the nucleus.
In 1897 Who discovered electrons
J.J Thompson
Who modelled the plum pudding model
J.J Thompson
Who discovered the nucleus
Ernest Rutherford
What are radioactive substances
Substances that decay radioactively
What is a property about radioactive decay
It is random
What are the 3 ways of detecting radioactivity
Geiger counter
Photographic film
Cloud Chamber
What is radiation dose measured in
Sieverts
What is nuclear fission
nuclear fission is the splitting of a large and unstable nucleus (e.g. uranium or plutonium) into smaller nuclei which can further split into more nuclei causing chain reactions. only happens when the initial nucleus absorbs a neutron
How can scientists use a controlled fission chain reaction
For energy in a nuclear reactor
How can an uncontrolled chain reaction be used
For nuclear weapons
What is nuclear fusion
When two light nuclei are joined together to form a heavier nucleus. Some of the nucleus mass can be converted to energy and released as radiation
