Which of the following is TRUE about a solution?a.It is always a liquid.b.It is a pure substance.c.Its appearance has one phase.d.It can be metal or nonmetal.

The correct answer is c. Its appearance has one phase.

Here's why:

a. It is always a liquid - This is not true. Solutions can be in the form of gas, liquid, or solid. An example of a gaseous solution is air (oxygen and other gases dissolved in nitrogen). An example of a solid solution is steel (carbon dissolved in iron).

b. It is a pure substance - This is not true. A solution is a mixture of two or more substances. It is not a pure substance.

c. Its appearance has one phase - This is true. A solution is a homogeneous mixture, which means it appears as a single phase. The solute is uniformly distributed within the solvent.

d. It can be metal or nonmetal - This is not entirely true. While a solution can contain metals or nonmetals, the solution itself is not classified as a metal or nonmetal.