What information is not given by an overall equation for a chemical reaction?

a) the number of atoms participating in the reaction

b) the reaction mechanism

c) the relative numbers of molecules used

d) the probable order of the reaction

Option (b) is the correct answer.

Explanation:

A chemical equation is an equation in which participating atoms that are written on left hand side are known as reactants and atoms that are written on right hand side are known as products.

For example,

Also, a reaction equation will help us determine the order of a reaction when it shows elementary step.

But a reaction equation does not show the mechanism of the reaction.

Hence, we can conclude that information that is not given by an overall equation for a chemical reaction is the reaction mechanism.

The sun is already about 4.5 billion years old, it is expected that in about another 4.5 billion years it will consume all its hydrogen and expand to form a red giant, after that it will burn iron for about another billion years and convert into a white dwarf so i'd say it is an insanely long time.