Here's a breakdown:

* Metallic elements: These are elements that are typically shiny, malleable, ductile, and good conductors of heat and electricity. Examples include:

* Alkali metals (Li, Na, K, Rb, Cs, Fr)

* Alkaline earth metals (Be, Mg, Ca, Sr, Ba, Ra)

* Transition metals (Fe, Cu, Au, Ag, etc.)

* Non-metallic elements: These are elements that lack the typical properties of metals. They are often brittle, dull, and poor conductors. Examples include:

* Halogens (F, Cl, Br, I, At)

* Noble gases (He, Ne, Ar, Kr, Xe, Rn)

* Oxygen, nitrogen, carbon, sulfur, phosphorus, etc.

Examples of non-metallic compounds:

* Water (H₂O): Made of hydrogen and oxygen, both non-metals.

* Carbon dioxide (CO₂): Made of carbon and oxygen.

* Ammonia (NH₃): Made of nitrogen and hydrogen.

* Sugar (C₁₂H₂₂O₁₁): Made of carbon, hydrogen, and oxygen.

* Methane (CH₄): Made of carbon and hydrogen.

Key characteristics of non-metallic compounds:

* Wide range of properties: Non-metallic compounds can be solids, liquids, or gases at room temperature. They can have varying colors, densities, and solubilities.

* Diverse applications: Non-metallic compounds have countless applications in various fields, including:

* Pharmaceuticals

* Agriculture

* Manufacturing

* Food industry

* Energy production

Remember, a compound is considered non-metallic if it does not contain any metallic elements in its composition.