Atomic structure
What are the three subatomic particles?
Protons, neutrons, electrons
What are isotopes?
Atoms with different numbers of neutrons
What is radioactivity?
The release of radiation from unstable nuclei
What is half-life?
Time for half the radioactive nuclei to decay
Which radiation is the most penetrating?
Gamma
What charge does a proton have?
Positive (+)
What is the charge of a neutron?
Neutral (0)
Name one type of radiation.
Alpha, beta, or gamma
What fraction remains after one half-life?
One-half
Who discovered radioactivity?
Henri Becquerel
Where are electrons found?
Outside the nucleus
How do you find the number of neutrons?
Mass number − atomic number
Which radiation is positively charged?
Alpha
What percentage remains after one half-life?
50%
What does ionising radiation do?
Removes electrons from atoms
What does the atomic number tell you?
Number of protons
Do isotopes have the same number of protons?
yes
Which radiation is negatively charged?
Beta
What percentage remains after two half-lives?
25%
Name one use of radioactive isotopes.
X-rays
What is the mass number?
Protons + neutrons
How many neutrons does carbon-14 have?
8
Which radiation has no charge?
Gamma
A sample has 80 g. How much remains after one half-life?
40 g
Why can radiation be dangerous?
It can damage cells and DNA