How much of a 6gram sample of silver-105m would remain after 4 minutes?

Question

Half life=7.2 minutes

Answer 1

k = 0.693/t_1/2
Substitute k into the equation below.
ln(No/N) = kt.
No = 6
N = unknown
k = from above
t = 7.2 min
I get approximately 4 g remaining.

Answer 2

Great! But, so that I can understand it in the future, can you tell me what the value of k is a little more clearly? how do you do a subscript of 1/2?

Answer 3

The half life is given in the problem (last line you typed) of 7.2 minutes.
I write a t_1/2
To turn on subscript type < followed by sub followed by >. Then type the 1/2. To turn subscript off type < followed by /sub followed by >