The half-life for beta decay of strontium-90 is 28.8 years. a milk sample is found to contain 10.3 ppm strontium-90. how many years would pass before the strontium-90 concentration would drop to 1.0 ppm? the half-life for beta decay of strontium-90 is 28.8 years. a milk sample is found to contain 10.3 ppm strontium-90. how many years would pass before the strontium-90 concentration would drop to 1.0 ppm? 131 96.9 0.112 92.3 186

96.9 years would pass before the strontium-90 concentration would drop to 1.0 ppm.

Explanation:

Given that:

Half life = 28.8 years

Where, k is rate constant

So,  

The rate constant, k = 0.024067 years⁻¹

Using integrated rate law for first order kinetics as:

Where,  

is the final concentration= 1.0 ppm

is the initial concentration = 10.3 ppm

Time = ?

So,  

t = 96.9 years

96.9 years would pass before the strontium-90 concentration would drop to 1.0 ppm.

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .