The decay constant, denoted by λ (lambda), is a measure of the rate at which a radioactive substance decays. It is related to the half-life (T1/2) of the substance through the equation:
λ = ln(2) / T1/2
Where ln(2) is the natural logarithm of 2, approximately equal to 0.693. Given that the half-life of the radioactive material is 12 days, we can calculate the decay constant as follows:
λ = 0.693 / 12 ≈ 0.05775 per day
Therefore, the decay constant for the radioactive material is approximately 0.05775 per day.