Which accounts for most of the mass of an atom? electron
protons
neutrons and protons
electrons and neutrons

The majority of an atoms mass comes from the protons and neutrons.

This is what i found on google“ the monomers combine with each other via covalent bonds to form larger molecules known as polymers. in doing so, monomers release water molecules as byproducts. this type of reaction is known as dehydration synthesis, which means “to put together while losing water. in the process, a water molecule is formed.” i hope this you