Which of the following property does not describe a compound?
It is mixed in any proportion by mass
A compound is a pure substance formed when atoms of two or more elements chemically combine with each other in a fixed proportion.
Their properties are distinct from the properties of elements constituting them. For example, hydrogen and oxygen combines in a fixed ratio of 2:1 to form water. Hydrogen is combustible and oxygen is a supporter of combustion. However, water is used as a fire extinguisher.