Answer:
15 h
Explanation:
Okay, the first thing that we all have to know before we can answer this question is that this Topic that is, Chemistry of Radioactivity is related to kinetics in a way that Radioactive disintegration follows the first order of Reaction which is under kinetics. So, we will be using the first order kinetics rate law to answer this question. Using the equation (1) below;
k =[ 2.303/ t ]×log ([N°}/ [Nr]) --------(1).
We are given from the question that N° = initial sample = 0.8 mg and Nr= sample remaining = 0.2 and the time taken = t= 30.0 h.
k= (2.303/ 30.0 h ) × log (0.8/0.2).
k=0.076768 h^-1 × log (4).
k= 0.076768 h^-1 × 0.6021.
k= 0.0462 h^-1.
Therefore, using the formula for Calculating half life below for first order kinetics we will be able to find out answer.
k = ln 2/ t(1/2). Where t(1/2) is the half life.
t(1/2) = ln 2/ k.
t(1/2) = ln 2 / 0.0462 h^-1.
t(1/2)= 0.6931/0.0462 h^-1.
t(1/2)=15 h
The chemical formula for this compound would be V2O5.
<span>The DNA or deoxyribonucleic acid is composed of a pentose sugar,
a base and phosphate group. The bases are adenine, thymine, cytosine and
guanine. Guanine always forms hydrogen bonds with cytosine. Remember the
statement “Apples in the Tree, Cars in the Garage”. The A stands for adenine
and pairs with T-thymine then C – cytosine and G – guanine. </span>
Answer:
B
Explanation:
I mean just think about it where else are the particles going to move? The room right?