Americium-241 is a radioactive substance used in smoke detectors. the half life of americium is 432 years. if a smoke detector initially contains 1 gram of americium 241, how much will remain in 432 years?
question 4 options:
0.5 grams
1.0 grams
1.5 grams
2.0 grams

Answer : The correct option is, (2) 0.5 grams

Solution : Given,

As we know that the radioactive decays follow first order kinetics.

First we have to calculate the half life of Americium-241.

Formula used :

Putting value of half-life in this formula, we get the rate constant.

The expression for rate law for first order kinetics is given by :

where,

k = rate constant  =

t = time taken for decay process  = 432 years

a = initial amount of the Americium-241 = 1 g

a - x = amount left after decay process  = ?

Putting values in above equation, we get

Therefore, the amount remain in 432 years will be, 0.5 grams

air quality

poor drinking water

and heavy polution

can lead to poor health

answer: the primary difference between a hypothesis and a theory is that b hypothesis is falsifiable, but a theory has been proven to be correct. theory is an explanation of something that is happening but hypothesis is a guess of something that can happen

explanation: