Answer:
carbon monoxide is a pure substance because it cannot be separated by any physical method.
Explanation:
A pure substance is also known as chemical substance, it is a form of matter having constant chemical composition and characteristic properties.
Also a pure substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds.
A mixture of milk and water (tea) can be separated by filtration (physical method).
A mixture of of sugar and water can be separated by distillation (physical method).
Also a casserole, pomegranate juice are separated using physical methods.
However, carbon monoxide constant chemical composition and characteristic properties, and it cannot be separated by physical method.
Therefore, carbon monoxide is a pure substance.