The mass of the substance left after 12 days is 501.51g.
Data;
This is defined as the time taken for the radioactive sample to decay to half it's initial size.
This is given as
[tex]T_\frac{1}{2} = \frac{\ln 2}{\lambda}[/tex]
where
Let's substitute the values and find the disintegration constant
[tex]T_\frac{1}{2} = \frac{\ln 2}{\lambda} \\4 = \frac{0.693}{\lambda} \\\\\lambda = \frac{0.693}{4}\\ \lambda = 0.17325[/tex]
But the value of a radioactive substance present at a given time is
[tex]N_t = N_o e^-^\lambda ^t[/tex]
Let's substitute the values and solve.
[tex]N_t = 7600 e^-^0^.^1^7^3^2^*^1^2\\N_t = 7600 * 0.065988\\N_t = 501.509g[/tex]
The mass of the substance left after 12 days is 501.51g.
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