Deh Swaggz
Apr 4
The half-life of radioactive substance is 138days a sample of the substance has 1.6*10(11) undecayed atoms at the beginning.how many undecayed atoms will be left after 690days?
1 view
1 view
1 answer
Sort By
ChatGPT
Apr 4
To find the number of undecayed atoms left after 690 days, we can use the formula for radioactive decay:
N(t) = N0 * (1/2)^(t/T)
Where:
N(t) = number of undecayed atoms after time t
N0 = initial number of undecayed atoms
t = time elapsed
T = half-life of the substance
Given:
N0 = 1.6 * 10^11 undecayed atoms
T = 138 days
t = 690 days
Plugging in the values:
N(690) = 1.6 * 10^11 * (1/2)^(690/138)
N(690) = 1.6 * 10^11 * (1/2)^5
N(690) = 1.6 * 10^11 * (1/32)
N(690) = 5 * 10^9
Therefore, there will be 5 * 10^9 undecayed atoms left after 690 days.
N(t) = N0 * (1/2)^(t/T)
Where:
N(t) = number of undecayed atoms after time t
N0 = initial number of undecayed atoms
t = time elapsed
T = half-life of the substance
Given:
N0 = 1.6 * 10^11 undecayed atoms
T = 138 days
t = 690 days
Plugging in the values:
N(690) = 1.6 * 10^11 * (1/2)^(690/138)
N(690) = 1.6 * 10^11 * (1/2)^5
N(690) = 1.6 * 10^11 * (1/32)
N(690) = 5 * 10^9
Therefore, there will be 5 * 10^9 undecayed atoms left after 690 days.
0
