need help with half-life for pre-cal?

Question

were doing half-life in pre-cal but i did it in chem and forgot. need help

half-life of a certain radioactive substance is 14 days. there are 6.6grams presnt initially.

what is the rate of decrease?
what is the growth factor?(can u also tell me what that means, thanks)

Answer 1

The decay constant (λ) is probably what you're looking for in the rate of decrease.

half life = ln 2 / λ
so: λ = ln 2 / half life

Not sure what it's looking for when it asks for "growth factor" - the assignment or textbook should have a definition for that term if it's going to use it.

Answer 2

y = Ce^(kt) y is very final mass, C is preliminary mass, ok is the relative decay ingredient, t is time (2.) a million/2 = e^(1590k) ln(a million/2) = 1590k ok = ln(a million/2)/1590 ok ? -0.000436 while you're utilising a calculator, shop utilising this authentic type. Rounding this early could make your very final answer off by skill of a few extra digits. y = 100e^(ok(2000)) y = 100e^(2000 ln(a million/2)/1590) y ? 40-one.816 mg ------------------------ (3.) a million/2 = e^(4k) ln(a million/2) = 4k ok = ln(a million/2)/4 ok ? -0.173 4 = Ce^(12k) C = 4/(e^(12k)) C = 32 mg After 5 weeks: 5 weeks = 35 days (you could replace to days because of the fact the a million/2-existence is in this unit.) y = 32e^(35k) y = 32e^(35*ln(a million/2)/4) y ? 0.0743 mg