Chemical Compound

A chemical compound is a substance made when two or more different chemical elements are chemically bonded together in fixed proportions. Every pigment, binder, solvent, or additive used in painting is made of one or more chemical compounds.

1. A chemical compound is a pure substance consisting of two or more different elements chemically bonded together in a specific ratio. Unlike a mixture, the elements in a compound cannot be separated by physical means because they form a new substance with its own unique chemical and physical properties.Compounds can be:
   • Organic compounds, which contain carbon and are common in oils, acrylic polymers, and many solvents.
   • Inorganic compounds, which generally do not contain carbon and include many mineral pigments such as titanium dioxide, iron oxides, and cobalt aluminate.

   In painting, understanding compounds helps explain why different pigments have distinct characteristics such as color, opacity, tinting strength, permanence, toxicity, drying behavior, and lightfastness.

When artists read a pigment’s chemical composition, they are looking at the compound that gives the material its properties. Different compounds containing the same element can behave very differently. For example, cobalt appears in several blue and green pigments because it forms different compounds with other elements, each producing a distinct color and performance.

• A compound is made of two or more different elements chemically bonded together.
• Compounds have properties that are different from the individual elements that compose them.
• Each compound has a fixed chemical formula (for example, CoAl₂O₄ or TiO₂).
• Many pigments, binders, and painting materials are specific chemical compounds.
• A compound is different from a mixture, where substances are simply combined without forming chemical bonds.