Zusammenfassung der Ressource
Radioactivity
- Key Definition
- Half-Life
- Either:
- The time taken for the activity to halve.
- The time taken for the number of undecayed nuclei to halve.
- Activity
- The number of decays per second.
- Isotope
- An atom of an element with the same number of
protons but a different number of neutrons.
- Radioisotope
- An unstable isotope that will
undergo radioactive decay in order
to become more stable.
- Radioactive Decay
- The act of spontaneous and
random release of radiation.
- Ion
- An atom with a charge.
- Ionisation
- The act of causing an atom to become an ion.
- Radiation
- Background Radiation
- Some materials give off radiation naturally.
- For example:
Rocks, Air and
Space.
- There are three types of radiation.
- Alpha
- Beta
- Gamma
- They are stopped by
different materials.
- Radiation Flashcards.
Anlagen:
- Atomic Structure
- Previously, people believed
that the atom looked like a
'plum pudding'.
- Rutherford Scattering Experiment
- Ernest Rutherford, a British scientist,
proved that the atom had a positive
nucleus with negative electrons orbiting it.
- Alpha particles were
fired at thin gold foil.
- Most particles went through,
whilst some were deflected and
the rest were reflected.
- As most past through easily, the
atom is mainly empty space.
- A few were deflected, so...
- Some were reflected, so...
- The nucleus is small compared to the rest of the
atom, yet it contains most of the mass and of the
positive charges.