Answer:
0.0957 g
Explanation:
Half life is the time required by the substance to decay to half of its initial mass. Most often exponential decays of radioactive substances are explained by half life. Half life remains constant throughout the life of decay.
It is given as;
<em> N</em>(t) = N₀ (1/2)^t/t1/2
Where;
<em>N</em>(t) = Amount remaining after certain time
N₀ = The starting initial amount
t1/2 = Half life of given substance
Putting values,
<em> N</em>(t) = 98 × (1/2)^215/21.5
<em> N</em>(t) = 0.0957 g
