Answer:
13.5 years
Explanation:
Initial Concentration [Ao] = 10g
Final Concentration [A] = 0.768g
Time t= 50 years
Half life t1/2 = ?
These quantities are related by the following equations;
ln[A] = ln[Ao] - kt ......(i)
t1/2 = ln(2) / k ...........(ii)
where k = rate constant
Inserting the values in eqn (i) and solving for k, we have;
ln(0.768) = ln(10) - k (50)
-0.2640 = 2.3026 - 50k
50k = 2.3026 + 0.2640
k = 2.5666 / 50 = 0.051332
Insert the value of k in eqn (ii);
t1/2 = ln(2) / k
t1/2 = 0.693 / 0.051332 = 13.5 years
I think it is b. Ga, Ge, As, Se
It's important because you don't what it hit no beetles in the city
Under STP condition, the gas has a rule of 22.4 L per mole. And according to the ideal gas law, V1/T1=V2/T2. Under STP, 1.5 mol gas has volume of 33.6 L. So the volume under 22 C is 33.6*295/273=36.3 L.

1. we used <u>Symbol</u> to represent an element.
2. The chemical formula of a molecule shows the <u>number and kind of atoms contained in the molecule</u>.
3. K (potassium) is the atom among the given choices.
4. CO (carbon - monoxide) is the molecule among given choices.