Introduction to Chemistry

This lesson will go over the very interesting topic of energy—the ability to perform some sort of activity or generate heat. You'll learn the difference between potential and kinetic energy. You'll also learn about three different types of temperature scales and how to convert temperature readings from one scale to another. The lesson will discuss joules and calories, two other units that measure energy, and talk about the kilocalorie (Calorie), a way to measure the energy value in food. You'll examine the topic of specific heat and learn why the high specific heat of water is so important to your body. At the end of the lesson, there will be a discussion of endothermic and exothermic reactions and how they relate to the food that you eat. Along the way, you'll perform some activities to help you understand the material in this lesson.

In this lesson, you'll explore measurements in chemistry. You'll focus on volume, length, mass, and density and compare the United States's system of measurement with the metric system of measurement. You'll learn why scientists and health care professionals primarily use the metric system and how to convert from one system to another. The lesson will also discuss the difference between mass and weight, and introduce you to the topics of density and specific gravity. In the last chapter, you'll take a look at a sample lab report to tie all these topics together.

In this lesson, you'll learn about the structure of an atom. You'll examine the three major subatomic particles—protons, neutrons, and electrons. You'll learn about their location, electrical charges, and relative sizes, and how chemists count how many subatomic particles are present in an atom of an element. The lesson will also talk about the difference between atoms and ions, and you'll learn which subatomic particles can vary in number in the atoms of an element. You'll also study the way electrons fill energy levels around the nucleus of an atom. The lesson will end with a discussion of the use of radioactive isotopes in medicine.

In this lesson, you'll explore the organization of the Periodic Table of the Elements. You'll learn about a famous Russian scientist who's known as the father of the modern periodic table, and why the development of this table was so important. The lesson will talk about the three major classes of elements—metals, metalloids, and non-metals, and you'll learn about their major characteristics. You'll also learn about some specific elements and the roles they play in the function of your body. You'll revisit the topic of valence electrons, and discover why they determine whether or not atoms of an element will combine with other atoms. Finally, you'll examine the very important role that the element iron plays in your body and learn about a condition called iron deficiency anemia.

This lesson will cover four types of chemical bonds—true covalent, polar covalent, ionic, and hydrogen bonds. You'll learn what these bonds have in common with romantic relationships and discover which of these bonds are strong and which are weak. The lesson will also talk about different ways that scientists represent molecules, and you'll learn about molecular, structural, and electron-dot formulas. You'll study the concept of electronegativity and find out how differences in electronegativity determine the types of bonds that are formed.

In this lesson, you'll explore the language of chemical equations. You'll learn how to interpret the letters, symbols, and numbers that are used to write chemical equations. The lesson will talk about the differences between reactants and products, and you'll come to understand the importance of the Law of Conservation of Mass. The lesson will take the mystery out of balancing chemical equations, and you'll go over a step-by-step method for balancing them yourself. You'll also study the topic of chemical equilibrium and the importance of reversible reactions.

In this lesson, you'll explore the fascinating topic of chemical kinetics. You'll learn about the different factors that cause chemicals to react with each other and how the temperature, physical nature, orientation, concentration, and pressure of the reactants affect the speed of chemical reactions. You'll also learn about a concept called activation energy—the minimum amount of energy needed for a chemical reaction to occur. The lesson will also discuss catalysts—chemicals that speed up chemical reactions but aren't changed themselves. You'll learn how important enzymes (biological catalysts) are for the function of your body and what can go wrong when an enzyme is missing.

In this lesson, you'll explore the topic of stoichiometry—this fancy word simply means the quantitative relationship between reactants and products. One type of stoichiometry calculation, for example, tells you how much product you can make if you have a certain amount of reactants. Another type tells you the reverse—how much of a reactant you need if you want to make a certain amount of product. To learn how this is possible, you have to know about a special number called "Avogadro's number," and that's something else you'll find out about in this lesson. This number tells you how many particles of a substance are contained in a "mole," and you'll discover how these units allow you to perform many stoichiometric calculations. The end of the lesson will include a discussion about the importance of oxygen in your body and how it limits the amount of energy you can generate from the food you eat.

In this lesson, you'll go over some basic information about solutions. You'll start out by learning about the different types of mixtures and then spend the rest of the lesson on the topic of solutions, which are a special type of mixture. Solutions are important to understand because almost all chemical reactions that occur in the human body occur in a solution, and many medications are administered in a solution as well. You'll learn the difference between solutes and solvents and find out why chemists call water the universal solvent. Water can't dissolve every kind of substance, though, and you'll learn the reason why that's true. The lesson will talk about conditions that affect how easy it is to make a solution, and you'll discover the difference between unsaturated and saturated solutions. Finally, the lesson will teach you how to solve some basic concentration problems and will then include an interesting discussion about water-soluble and fat-soluble vitamins.

In this lesson, you'll review chemicals called acids, bases, and salts. You'll learn about their behavior in water and about their unique characteristics. The lesson will discuss the differences between concentrated and dilute solutions, and between strong acids and bases. You'll also discover how buffers work to reduce the level of acidity in a solution. The pH scale measures the level of acidity in a solution, so you'll spend some time on that as well. You'll learn that the pH of fluids in your body must stay within a certain range and what happens when it doesn't. At the end of the lesson, there will be a discussion of several disorders that may occur when the levels of ions get out of balance.

The final lesson will go over four types of bioorganic molecules—carbohydrates, lipids, proteins, and nucleic acids. You'll come to know the difference between inorganic and organic molecules and find out why the unique structure of carbon atoms makes it possible for millions of different organic molecules to exist. You'll then move on to a discussion about the chemical structure of the four types of bioorganic molecules. You'll learn about their chemical building blocks and how these building blocks come together to form these large molecules. You'll also learn about their important functions and how much your body depends on their presence.