Physics Homework 11.1.25 Flashcards
[Atomic Structure Revision]
Define radioactive contamination.
The unwanted presence of materials containing radioactive atoms on other materials.
State what a gamma ray is made of.
Electromagnetic radiation (a high energy wave)
Name the experiment that discovered the nucleus of an atom.
The alpha particle scattering experiment.
Define irradiation.
The process of exposing an object to nuclear radiation.
State whether irradiated object become radioactive.
No, because their nuclei do not become unstable.
Describe what happens to the atomic number of an element of a beta particle is emitted.
It increases by one.
Describe what happens to the half-life of a radioactive sample over time.
Nothing, it stays constant forever.
State what a beta particle is made up of.
A fast moving electron.
Describe what happens to the activity of a radioactive sample over time.
It decreases.
Describe how a nucleus emits beta radiation if the nucleus has no electrons in it.
A neutron in the nucleus turns into a proton, emitting an electron in the process.
Explain how the alpha particle scattering experiment proved that the nucleus was positively charged.
Alpha particles were deflected and some were scattered backwards due to the repulsion.
Define half-life in terms of activity.
The time it takes for the radioactive activity of a sample to halve.
State the range of gamma radiation in air.
Many kilometres.
List the three types of ionising radiation from most ionising to least ionising.
Alpha, Beta, Gamma
State what an alpha particle is made of.
Two protons and two neutrons (a Helium nucleus)
List the three types of ionising radiation from most penetrating to least penetrating.
Gamma, Beta, Alpha
Describe what happens to the mass number of an element if a beta particle is emitted.
It stays the same.
Describe the structure of an atom.
A central nucleus comprised of protons and neutrons surrounded by electrons.
Describe what happens to the atomic number of an element if an alpha particle is emitted.
It decreases by two.
Describe what happens to the mass number of an element if an alpha particle is emitted.
It decreases by four.
