Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value. The equation to describe the decay is
Nt=N0(1/2)

where N0 is the initial quantity, Nt is the remaining quantity after time t, t1/2 is the half-time. So work out the equation, t1/2 = t (-ln2)/ln(Nt/N0) = 11.5*(-ln2)/ln(12.5/100) = 3.83 days
I believe the correct answer from the choices listed above is the first option. During a physical change, m<span>olecules can move more rapidly and freely and change states. Such action, would not disrupt or destroy the nature of the molecules they will still have the same molecular structure. Hope this answers the question.</span>
Answer:
V₂ = 1518L
Explanation:
-Using combined gas law:

<em>Where P is pressure, V is volume and T is absolute temperature of 1, initial state and 2, final state of the gas.</em>
<em />
<em>Initial states:</em>
P₁ = 743 torr
V₁ = 975L
T₁ = 30°C + 273.15K = 303.15K
P₂ = 375 mmHg = torr
V₂ = Our incognite
T₂ = -35°C + 273.15K = 238.15K
Replacing:

<h3>V₂ = 1518L</h3>
Answer: I'm going to guess and say it is h2 or o2 I am not sure.
Explanation: