07 Radioactivity and Particles 4th Flashcards
Name the three types of radioactive particles?
alpha, beta, gamma
Describe an alpha particle
It is a helium nucleus
Describe a beta particle
It is a high speed electron
Describe gamma radiation
EM wave
travels at the speed of light
No charge or mass
Name the subatomic particles in an atom
proton
neutron
electron
What are the relative masses of the proton, neutron and electron?
proton = 1
neutron = 1
electron = 0
Define the atomic number
number of protons in an atom
Define the mass number
Number of protons + neutrons in an atom
What is another name for the mass number?
nucleon number
What are the relative charges of the proton, neutron and electron?
proton = +1
neutron = 0
electron = -1
Where are the electrons found in an atom?
In shells in the space around the nucleus
Where are the protons and neutrons found in the atom?
in the nucleus
atoms are neutral, so what is true about the number of protons and electrons?
number of protons = number of electrons
What is an isotope?
Atoms of the same element with same number of protons but different number of neutrons.
Two common isotopes of carbon are C-12 and C-14
(Carbon has an atomic number of 6)
Name one similarity and two differences about these isotopes?
They both have 6 protons
C-14 has 8 neutrons but C-12 only has 6 neutrons.
C-14 is an unstable isotope of carbon and C-12 is a stable isotope
What is another name for an unstable isotope?
radioisotope or radioactive isotope
Why does an unstable isotope break down?
An unstable isotope has too many or too few neutrons in the nucleus which makes it emit alpha, beta, neutron or gamma radiation
Name four types of radiation
alpha
beta
neutrons
gamma
Radioactive isotopes decay spontaneously.
What does this mean?
It means that you can’t say when any one of them is going to decay and you can’t do anything to at all to make a decay happen. It is a random process.
Which type of radiation occurs without changing the radioisotope into a new element?
gamma
Name the three types of radiation which will change a radioisotope into a new element.
alpha
beta
neutrons
There is low level background radiation all around us all the time. It comes from….
- Rocks, soil, buildings and food (from Earth)
- cosmic rays from space
- living things
- radiation due to human acitvity - nuclear waste, nuclear fall-out
Nuclear radiation causes ionisation. What is ionisation?
When radiation bashes into atoms, knocking electrons from them.
These atoms are turned into ions which are charged
How can we detect ionising radiation?
Geiger-Muller tube - GM tube OR photographic film
Radiation is less penetrating if it is….
more highly charged
more massive
slower moving
Radiation is more penetrating if it is….
less charged
less massive
faster moving
Radiation is more ionising if it is….
more highly charged
more massive
slower moving
Radiation is less ionising if it is….
less charged
less massive
faster moving