Atomic structure and Radiation YEAR 9 Flashcards
Explain rutherford bohr’s gold foil experiment
Positive alpha particles shot at gold foil
Most passed through (no repulsion)
A few bounced back (same-pole repulsion)
This proved that atoms have a small positive nucleus at the centre
Define radioactive decay
The disintegration of unstable nuclei, which emits a tiny particle.
What are the three types of nuclear radiation
Alpha particles
Beta particles
Gamma rays
Which type of nuclear radiation is the most penetrating
Gamma rays
Which type of nuclear radiation is the least penetrating
Alpha particles
What is the charge of alpha particles
Posotive
What charge are the beta particles
negative
What charge are gamma rays
No charge
What is the most ionising form of nuclear radiation
Alpha particles
What is the least ionising form of nuclear radiation
Gamma rays
Why is nuclear radiation dangerous to us
It is ionising
This can kill cells and cause DNA mutation
How is radiation used to destroy tumours
A strong beam of gamma rays is aimed at the cancerous tissue. The cancerous tissue is killed due to the radiation exposure.
How are medical tracers used to explore internal organs
Emits gamma rays that easily pass through the body to a detector outside the body
The radioactive source can be followed as it flows through a particular organ in the body.
define half life
the time it takes for half of the unstable nuclei in a sample to decay or the activity to halve
Define nuclear fission
A neutron collided with a large nucleus, splitting it into two smaller nuclei
