What sorts of signals does the brain use to communicate sensations, thoughts and actions?

In numbering carbon atoms in the parent chain of a hydrocarbon, why would you number from right to left, rather than left to right

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both