If the half-life of 37rb is 4.7x101 years, how long would it take for 0.5 grams of a 2 gram sample to radioactively decay?

The time required will be 19.18 years

Explanation:

All the radioactive reactions follows first order kinetics.

The equation used to calculate half life for first order kinetics:

We are given:

Putting values in above equation, we get:

Rate law expression for first order kinetics is given by the equation:

where,  

k = rate constant  =

t = time taken for decay process = ?

= initial amount of the reactant = 2 g

[A] = amount left after decay process =  (2 - 0.5) = 1.5 g

Putting values in above equation, we get:

Hence, the time required will be 19.18 years

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

the answer is a for sure mark brainliest i had got this right on usatestprep