How many electrons does it take to fill the outer shell of oxygen

The table describes how some substances were formed substance 19 description formed by boiling pure water formed by combining three hydrogen atoms to every nitrogen atom formed by adding 5 g of sugar to 1 l of water formed by compressing carbon under high pressure based on the given descriptions, which substance is most likely a mixture?

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins