State in terms of subatomic particles how an atom of c 13 is different from an atom of c 12

Calculate the expected ph values of the buffer systems from the experiments (a,b,c,d), using the henderson- hasselbalch equation, ph-pka+log[a-]/[ha]. use for pka values carbonic acid= 6.37, and acetic acid= 4.75.

Water's surface tension and heat storage capacity are accounted for by its a) orbitals b) weight c) hydrogen bonds d) mass e) size

Consider the directing effects of the substituents on salicylamide and predict the possible structures of the iodination products. which do you think will be the major product?