alpha, beta and gamma - science help

I've moved this to the Physics forum. Anything specific within that topic you're struggling with? In my experience half of it is just down to memorising the properties of each type of radiation.

They are three types of radiation.
You need to know the properties of them and where they are used.(check your specification to see what exactly you need to know about them)
What exactly don't you understand?
Also don't worry if you are struggling right now you have plenty of time and its good you're looking at these now

I'm stuck on half-life. i read my CGP book but i still don't get it

i'm stuck on half-life

What do you not understand about half-life? I recently did this topic and think I might be able to help.

As in you don't understand the concept of it? Or are you stuck on using it in calculations?

Basically radioactive substances have a half life.
The is a measure of how long it takes for them to decay by half (in simple terms)
When a substance is radioactive it is unstable and wants to become stable again.
So it will keep on decaying (emitting radiation) in order to become more stable

Say the radioactive substance has 20 radioactive nuclei to begin with
It decays (emits radiation) until there are only 10 radioactive nuclei (as this makes it more stable)
This takes 30 minutes
The half life of the radioactive substance is therefore 30 minutes.

Hope that helps. Feel free to ask any more questions.

THANK YOU SOOOOO MUCH !!!!! this really helped me

Just to carry on from that, half-life is the same no matter how many nuclei there are. So with those 10 remaining nuclei, in another 30 mins there will be 5 left. On average, since a nuclear decay is random and impossible to predict.

One example my GCSE physics teacher used was if you had a tray full of dice, you shook the tray, and you removed all the dice that were showing a 6 to simulate a radioactive decay. If you started out with 100 dice, it would take the same amount of time on average to get to 50 as it would to go from 50 to 25. The rate of the decay is actually proportional to how many nuclei you have.