the answer is mucus
The protective coating that forms on sheet lead is called lead oxide.
The metal that forms a self-protective coating when exposed to air and moisture is iron. This self-protective coating is known as iron oxide, or rust, which acts as a barrier to prevent further oxidation of the metal.
Cotton is the protective coating around cotton seeds. It forms as the cotton plant grows into a mature shrub.
a solid substance (s), a group 3 element, that forms a positive ion. it reacts with air, although this is not commonly known as it quickly forms a protective coating of aluminum oxide.
Nickel
Before they moult it, the protective coating of arthropods is referred to as the exoskeleton. The pieces of moulted exoskeleton after removal are called exuviae.
The white matter in the brain is created by myelin, which is a fatty substance that forms a protective coating around nerve fibers. Myelin helps to insulate and speed up the transmission of electrical signals between neurons.
Chrome
the protective protein coating
Fluoride protects your teeth by putting a protective coating on your teeth. The protective coating helps prevent bacteria from damaging your teeth.
Extra heavy soil pipe (CI) requires NO Coating
The protective structure that forms around a human embryo is called the amniotic sac or amnion. This sac contains amniotic fluid, which cushions and protects the developing embryo during pregnancy.