Which of the following statements are true for pure substances?
A. Pure substance contain only one kind of particles
B. Pure substance may be compounds or mixtures
C. Pure substance have the same composition throughout
D. Pure substances can be exemplified by all elements other than nickel
A pure substanceis an element or compound that has a constant chemical composition and property. It cannot be separated into components by physical separation, without breaking down chemical bonds. Substances which are commonly found in pure form include water, diamond, gold, table salt, brass, bronze and saline solution. It is free of contaminants, has a constant composition and resilient properties throughout the sample.
A pure substance produces chemical reaction to form expected products. It refers to an element or component that has no component to another compound or element. Pure substances have a specific boiling point and a particular melting point. The degree of purity of a substance is just the measure of the extent at which pure substances are present in an element.