How can information be transmitted across neurons when they are not in contact with one another.?

Through neurotransmitters.

Explanation:

There is a lot that goes into this like sodium pumps and potassium pumps. There is also the concept of diffusion.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.