Chapter 12: Basics of Chemistry: Review Questions

Explain the difference between elemental molecules and compound molecules. Give examples.

+Elemental Molecule: A molecule containing two or more atoms of the same element. +Compound Molecule: Also known as compounds, are a chemical combination of two or more atoms of different elements in definite (fixed) proportions.

What are the differences among between organic and inorganic chemistry?

+Organic Chemistry is the study of substances that contain the element carbon. +Inorganic Chemistry is the study of substances that do not contain the element carbon but may contain the element hydrogen.

What are the physical and chemical properties of matter? Give examples.

+Physical Properties are characteristics that can be determined without a chemical reaction and that do not involve a chemical change in the substance. +Chemical Properties are characteristics that can only be determined by a chemical reactions cause chemical changes.

Explain pure substances and physical mixtures. Give examples.

+Pure Substance is a chemical combination of matter in definite (fixed) proportions. +Physical Mixture is a physical combination of matter in any proportion.

Name and describe the three states of matter.

+Solid: Rigid; has fixed shape and volume +Liquid: Definite volume but takes the shape of its container. +Gas: No fixed volume or shape; takes the shape and volume of its container. Can never be liquid at normal temperatures or pressures

Define pH and the pH scale.

A pH scale is a measure of the acidity and alkalinity of a substance.

Explain oxidation-reduction (redox).

Also known as redox, is a chemical reaction in which oxidation and reduction take place at the same time.

What is matter?

Is any substance that occupies space and has mass (weight).

What are atoms?

Is the basic unit of matter with a nucleus at the center surrounded by negatively charged electrons (E) that move around the nucleus in orbits.

What is an element?

Is the simplest form of chemical matter.

What is chemistry?

The science that deals with the composition, structures, and properties of matter and how matter changes under the different conditions.

What are the differences among solutions, suspensions, and emulsions? Give examples.

•A solution is a stable physical mixture of two or more substances in a solvent. Example: When salt is dissolved in water, salt is the solute and water is the solvent. •Suspensions are unstable physical mixtures of undissolved particles on a liquid. Example: Glitter in a nail polish that can separate from the polish. •An emulsion is an unstable physical mixture of two or more immiscible substances, plus a special ingredient called an emulsifier. Example: hand lotion.

Why is a basic understanding of chemistry important to cosmetology?

•Without an understanding of basic chemistry, you would not be able to use professional products effectively and safely. •Every product used in the salon and in cosmetology services contains some type of chemical. •With an understanding of chemistry, you will be able to troubleshoot and solve common problems you may encounter with chemical services.