Why does coke explode when mentos is added?

1. What causes the chemical reaction??

2. does the amount of mentos added affect the explosion??

3. Is the chemical reaction harmful??

4. Does it happen to all mentos flavour??

4.1. Will the coke explode if mentos(mint) is added??

4.2. Will the coke explode if mentos(cola) is added??

4.3. Will the coke explode if mentos(strong mint) is added??

4.4. Hypothesis: