Three uses of compound in medicine and industrial use ​

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

Water is initially present in a state where its molecules are far apart. during a change of state, its molecules slow down. which change of state has most likely taken place? from a gas to a liquid from a liquid to a gas from a solid to a liquid from a gas to a plasma