Answer:
1)Reactants
2)Light
3)An item that can increase reaction rates
4)Reactants must collide with each other
Less molecules lower the chance for collisions
The more collisions there are the higher the reaction rate
I believe it's 6789 times 10^4. I could be wrong, due to the fact that I don't remember what's the definition of the scientific notion. I hope this helps, or at least gives you an idea! :D
There is 3800 mmHg in 5 atm