This is a chemical compound.
A substance made of two or more elements chemically combined in a specific proportion is called a compound. A substance composed of two or more elements combined chemically in a fixed proportion by mass is called a compound. A chemical compound can be held together by a covalent bond or an ionic bond.
Compound
molecule
a compound is a substance that contains two or more elements chemically combined in a fixed proportion while mixture is a physical blend of two or more substances that are not chemically combined
compound
Protein
A compound is composed of two or more elements chemically combined in a definite proportion. The components of a mixture are not chemically combined and can vary in proportion.
Calcium Carbonate is a compound as it contains 3 different elements (calcium, carbon and oxygen) that are chemically combined.
compound
Compounds are formed when elements of matter are chemically combined.
compound
A compound.