Humber Admissions Practice Test

What is a mixture?

1. A chemical reaction combining elements

2. A combination of two or more substances that are not chemically combined

3. A process creating a new substance

4. A solution of a single substance

The correct answer is: A combination of two or more substances that are not chemically combined

A mixture is defined as a combination of two or more substances that maintain their individual properties and are not chemically combined. This means that each component within the mixture retains its own characteristics, such as its physical properties and chemical identity, which distinguishes it from a compound where elements are chemically bonded to form a new substance. In a mixture, the substances can be solids, liquids, or gases, and they can be combined in varying proportions, resulting in a heterogeneous or homogeneous mixture. For instance, when you combine sand and salt, you can still see and separate the individual grains, which is a clear demonstration of a mixture. This characteristic is significant because mixtures do not undergo a chemical change and can often be separated through physical means, such as filtration or evaporation. Other options refer to processes or states that do not accurately describe a mixture. For example, a chemical reaction involves a transformative process where substances react to form one or more new products, making that definition incompatible with the concept of a mixture. Similarly, a solution typically describes a homogeneous mixture but implies that one substance has dissolved in another (such as salt in water), which is a specific type of mixture rather than a general definition. Therefore, the most accurate choice that encapsulates the essence of a mixture