Question

Which of the following is an example of pure substance?
A) Pure water.
B) Gold.
C) Table salt.
D) All of the above.

Answer 1

Hint: We know that everything that exists within the earth may be a sort of a matter which is further defined as any substance that occupies space and has mass. The matter is further divided into various forms like solid, liquid, and gas. It is again classified as pure substances and mixtures.

Complete step by step answer:

As we know that in chemistry, a substance is pure if it's a homogeneous chemical composition. At the nanoscale, this only applies to a substance made from one sort of atom, molecule, or compound.
In general, a pure substance is any homogeneous mixture. That is its matter that uniforms in appearance and composition, regardless of how small the sample size.
Iron, steel, and water are some of the examples of a pure substance. Air may be a homogeneous mixture that's often considered to be a pure substance. As we know diamond, sucrose, honey, and air all are pure substances.
Pure water has two hydrogens and one oxygen atom. These atoms are chemically bonded to every other. Also pure gold consists of gold atoms only. Salt (sodium chloride) can't be separated by physical means and features a constant chemical composition.
Therefore, all of the above examples are pure substances. i.e., the option D is correct.

Note:
Now we discuss about the characteristics and properties of pure substances:
Pure substances are mostly homogeneous containing just one sort of atom or molecules.
These substances mainly have a continuing or uniform composition throughout.
A pure substance usually participates during a reaction to make predictable products.