A water molecule consists of two hydrogen atoms bonded to an oxygen atom.

Understanding Molecular Structure:

Water Molecule: Consists of two hydrogen atoms and one oxygen atom chemically bonded together.

Classification of Substances:

Element (B): A pure substance of one type of atom.

Compound (D): A substance made of two or more different elements chemically bonded.

Isotope (C): Variants of a particular chemical element with different neutron numbers.

Mixture (A): A combination of substances not chemically bonded.

Chemical Bonding in Water: The hydrogen and oxygen atoms in a water molecule are chemically bonded, forming a compound.

Conclusion: Water is a compound.

References:

Chemical Compounds: Definitions and examples of chemical compounds.