Zoheb Imran said:How much of the substance was present in the sample 20 hours before the sample was tested?
Zoheb Imran said:why the other direction? can you please explain? that's where i am having problem...in calculating...
The formula for calculating half-life is: t1/2 = (ln 2) / λ, where t1/2 is the half-life, ln 2 is the natural logarithm of 2 (approximately 0.693), and λ is the decay constant.
The decay constant, denoted as λ, is a measure of the rate at which a substance decays. It is specific to each substance and can be found in a decay rate table or calculated using experimental data.
To convert grams to moles, you need to know the molar mass of the substance. You can find this by adding the atomic masses of each element in the substance. Then, use the formula moles = mass / molar mass to calculate the number of moles.
Yes, half-life can be used to predict future decay. The half-life of a substance is constant, so if you know the initial amount of the substance and its half-life, you can calculate the amount remaining after a certain amount of time has passed.
The formula for calculating the amount of a substance remaining after a certain number of half-lives is: At = A0(1/2)n, where At is the amount remaining after n half-lives, A0 is the initial amount, and n is the number of half-lives that have passed.