What characteristics should an isotope used for dating have?

Answer:B

Explanation: half-life of an element used in radioactive dating should be similar to the age of the fossil it is used to date.

The isotope can be defined as the substance that is used to determine the age of the substance which is usually a fossil (whose age is not known).

It should have longer time to decay which means its half life should be more in order to determine the age of the fossils which are billions year of age.

These isotopes are not stable and try to radiate rays in order to attain a stable state.

The half life of the substance whose age is not known is compared to these isotopes so that its relative age can be known using these isotopes.

Like Carbon 14 dating can be used for the organism of 5730 years approximately. Potassium-40 can be used for organism or fossil of age 100,000 years to origin of Earth.