What is the difference between `overset@A` and A.U.?

What is the difference between A^@ and AU?

What is the difference between gas and vapour?

What are the difference between vapour and gas?

What is the difference between lymph and blood?

What is the difference between isomers and conformers?

What is the difference between neutralisation and hydrolysis?

What is the difference between sol and gel?

What is the difference between a convex lens and concave lens?

What is the difference between carbon reduction and electrolytic reduction?

How are Delta H and Delta U are related? What is the difference between Delta Hand Delta U in a fusion process?