Elements are composed of identical atoms, compounds are composed of this

• A. Atoms.
• B. Molecules.
• C. Ions.
• D. Elements.

Answer: (B)

When we talk about what compounds are made from, the key idea is that they form when atoms bond together in fixed ratios. For most common compounds, the smallest identifiable unit is a molecule—two or more atoms held together by chemical bonds. So compounds are composed of molecules, which is why this option best fits. Elements, by contrast, are made of identical atoms and aren’t described as being built from molecules. Ions are charged particles and can form parts of some compounds, especially in ionic ones, but they don’t serve as the general unit that defines a compound.