The half-life of carbon-14 is 5370 years. the carbon-14 levels in a fossil indicate that 6 half-lives have passed. how old is the fossil?

32,220 years
75,200 years
50,000 years
35,000 years

35,000 years

Explanation: Radioactive process follow first order kinetics.

To calculate the rate constant, we use the formula:

Also :

where,  

a = amount of reactant left after n-half lives

= Initial amount of the reactant

n = number of half lives = 6

Putting values in above equation, we get:

The rate expression for first order kinetics is given by:

where,

k = rate constant

t = time taken for decay process

 = initial amount of the reactant

a = amount left after decay process

Putting values in above equation, we get:

b. latent learning (the word "latent" itself means something that exists but isn't obvious, only under certain conditions! )