Answer:
10.8 days (3 sig.figs.)
Explanation:
All radioactive decay is 1st order decay defined by the expression A = A₀e^-kt
which is solved for time of decay (t) => t = ln(A/A₀) / -k
A = final weight = 1.0 gram
A₀ = initial weight = 16.0 grams
k = rate constant = 0.693/t(1/2) = 0.693/2.69 days = 0.258 days⁻¹
t = ln(1/16) / -0.258da⁻¹ = (-2.77/-0.258) days = 10.74646792 days (calculator)
≅ 10 days (1 sig. fig. based on given 1 gram mass)
To answer the question above, substitute the given values to the given equation,
Q(t) = Q x e^-kt
12 grams = (36 grams) x e^(-0.00011)(t)
Solving for t gives t = 9,987.38 years or approximately equal to 9,990 years. Thus, the answer is letter C.
Gasoline, kerosene, and lighter fluid.
The iron nail displaces the Cu from the copper sulfate solution. This results in the color of CuSO4's disappearance. Copper is less reactive than iron.