P4 - What is radioactivity? Flashcards
1
Q
What is a geiger counter used for?
A
A geiger counter is used to detect the rate of decay of a radioactive substance.
2
Q
What is activity measured in?
A
Becquerels.
3
Q
What is the equation for activity?
A
activity = number of nuclei that decay/time in seconds
4
Q
What is the half life?
A
The half life of a radioisotope is the average time it takes for half the nuclei present to decay.
5
Q
What is a radioisotope?
A
A radioisotope has a nuclei that are unstable because its nuclear particles are not held together strongly enough.
6
Q
What is an alpha particle?
A
- positively charged
- large mass
- helium gas around it
- is a helium nucleus
7
Q
What is a beta particle?
A
- fast moving electron
- negatively charged
- small mass
- travels fast
8
Q
What happens when alpha or beta is emitted from the nucleus?
A
The nucleus becomes a different element.
9
Q
What happens when beta is emitted?
A
- the nucleus has one more proton
- the nucleus has one less neutron
- the atomic number increases by one
- the mass number is unchanged
