What is a group of protons and neutrons in the center of an atom called?

Which solution is an example of a nonelectrolyte? a. iodine in hexane b. sodium nitrate in waterc. acetic acid in waterd. hydrogen chloride in water

Seltzer water is created by placing water under pressure with carbon dioxide gas. which of the following statements best describe seltzer water: a. the solution will be slightly acidic b. the solution will be slightly basic. the solution will be strongly acidic. d. the solution will be strongly basic. e. the solution will be neutral

Which type of fossil does this image depict?