Will happen, might happen or won’t happen?

Look at the dark clouds. Will it rain? It might! We talk about the chance of things happening. Some things are sure; some are not.
Certain means it will definitely happen. Possible means it might happen. Impossible means it cannot happen.
On this spinner, red covers more space. The arrow is more likely to land on red. Landing on green is impossible – there is no green!
A bag has 5 orange sweets and 1 white sweet. If you pick without looking, you will probably get orange. Getting white is possible, but less likely.
Toss a coin 20 times and tally the results. We cannot know what comes next – it is random, not a regular pattern. But heads and tails come up about the same number of times.