Jovian planets are what we call the "gas giants," so immediately we can eliminate craters or volcanos because they don't have a solid surface. asteroids in space doesn't belong to any specific planet, so the answer is ring systems.
There should be mass balance and the charge balance between the reactants and the products
Mass balance : total no of individual atoms of each type should be balanced before and after the reaction
Charge balance : Overall charge of the reactants should be balanced with the overall charge of the products
You can balance,
1)by just looking at it
2)by Algebraic method given above or
3)by the redox method
You need to know how to get the oxidation numbers in order to use the oxidation method
Answer:

Explanation:
Half time is period required to desintegrating the half of the initial number of atoms. Then, the total time is:

