Radium decays according to the function where q represents the quantity remaining after t years and k is the decay constant 0.00043. how long will take for 40g of radium to decay to 10g?

For this problem, we use the formula for radioactive decay which is expressed as follows:

An = Aoe^-kt

where An is the amount left after time t, Ao is the initial amount and k is a constant. 

We calculate as follows:
An = 10 g

Ao = 40 g
k = 0.00043

An = Aoe^-kt
10 = 40e^-0.00043(t)
t = 3223.94 years

with btw u said 100pts but it clearly says

i answerd and just got 10pts

no hate

answer 1 : option "c"

answer 2 : option "d"

answer 3 : option "b"

answer 4 : option "d"

answer 5 : option "b"

answer 6 : option "a"

answer 7 : option "c"

answer 8 : option "d"

answer 9 : option "c"

answer 10 : option "d"

answer 11 : option "c"

answer 12 option "b"

answer 13 option "c"

answer 14 option "c"

answer 15 option "d"

answer 16 option "a"

answer 17 option "b"

answer 18 option "c"

answer 19 option "a"

answer 20 option "a"

answer 21 option "c"

d