Answer:
A, F, H
Explanation:
Hydrogen bonding occurs between compounds that make N-H, O-H, and F-H bonds. Just because a compound has a N, O, and F atom in the molecule doesn't mean that the compound will exhibit hydrogen bonding. The N, O, or F must be bonded to a hydrogen. Carbon-hydrogen bonds do not cause hydrogen bonding.
This means that A, F, and H will have hydrogen bonding.
The question is incomplete, here is the complete question:
The decay constant for 14-C is
In 1947, the famous cave paintings in Lascaux, France were discovered and testing revealed that charcoal in the cave contained 20% of the 14-C found in living trees. Write a formula for the age of the charcoal (hence of the associated paintings). Show your work to find this formula.
<u>Answer:</u> The formula for the age of the charcoal is 
<u>Explanation:</u>
Carbon-14 isotope is a radioisotope and its decay process follows first order kinetics.
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = ? yr
= initial amount of the sample = 100 grams
[A] = amount left after decay process = (100 - 20) = 80 grams
Putting values in above equation, we get:

Hence, the formula for the age of the charcoal is 
DDT stands for Dichlorodiphenyl Trichloroethane.DDT was used in theas a pesticide Second World War to protect the troops and civilians from the spread of malaria and other diseases. <span>Today DDT is used for insect control.
</span>But DDT harms the environment and the human health.
<span>There is an evidence that links DDT with severe declines in bald eagle populations due to thinning eggshells.</span>
So, DDT is dangerous environmental pollutant because it is toxic.