A new session of each course opens each month, allowing you to enroll whenever your busy schedule permits!
How does it work? Once a session starts, two lessons will be released each week, for the six-week duration of your course. You will have access to all previously released lessons until the course ends.
Keep in mind that the interactive discussion area for each lesson automatically closes 2 weeks after each lesson is released, so you’re encouraged to complete each lesson within two weeks of its release.
The Final Exam will be released on the same day as the last lesson. Once the Final Exam has been released, you will have 2 weeks plus 10 days to complete the Final and finish any remaining lessons in your course. No further extensions can be provided beyond these 10 days.
Lesson 01 - Understanding Matter
We'll start this course with a discussion of matter. Matter is anything that has mass and takes up space, so every structure in your body consists of matter. You'll learn about the three main states of matter (solids, liquids, and gases), where they are in your body, and how they change from one state to another. You'll also learn about the particles that make up matter, the differences between elements and compounds, and physical and chemical characteristics of substances. We'll end the lesson with a discussion of surface tension and its effect on premature babies.
Lesson 02 - Understanding Energy
In this lesson, we'll 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. We'll discuss joules and calories, two other units that measure energy, and we'll talk about the kilocalorie (Calorie), a way to measure the energy value in food. We'll examine the topic of specific heat, and you'll learn why the high specific heat of water is so important to your body. We'll end the lesson with 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.
Lesson 03 - Measurements in Chemistry
Today, we'll explore measurements in chemistry. We'll focus on volume, length, mass, and density and compare the United States' 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. We'll also discuss the difference between mass and weight, and I'll introduce you to the topics of density and specific gravity. In the last chapter, we'll take a look at a sample lab report to tie all these topics together.
Lesson 04 - The Structure of an Atom
In this lesson, you'll learn about the structure of an atom. We'll talk about 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. We'll 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. We'll also discuss the way electrons fill energy levels around the nucleus of an atom, and we'll end the lesson with a discussion of the use of radioactive isotopes in medicine.
Lesson 05 - The Periodic Table of the Elements
In this lesson, we're going to 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. We'll talk about the three major classes of elements—metals, metalloids, and non-metals, and you'll learn about their major characteristics. We'll also discuss some specific elements and some of the roles they play in the function of your body. We'll revisit the topic of valence electrons, and you'll discover why they determine whether or not atoms of an element will combine with other atoms. Finally, we'll discuss the very important role that the element iron plays in your body, and you'll learn about a condition called iron deficiency anemia.
Lesson 06 - Chemical Bonds
In today's lesson, we'll 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 you'll discover which of these bonds are strong and which are weak. We'll also talk about different ways that scientists represent molecules, and you'll learn about molecular, structural, and electron-dot formulas. We'll study the concept of electronegativity, and you'll find out how differences in electronegativity determine the types of bonds that are formed.
Lesson 07 - Chemical Equations
Today, we'll explore the language of chemical equations. You'll learn how to interpret the letters, symbols, and numbers we use to write chemical equations. We'll talk about the differences between reactants and products, and you'll come to understand the importance of the Law of Conservation of Mass. I'll take the mystery out of balancing chemical equations, and we'll go over a step-by-step method for balancing them yourself. We'll also discuss the importance of reversible reactions, and I'll introduce you to the topic of chemical equilibrium.
Lesson 08 - Chemical Kinetics
In today's lesson, we'll explore the fascinating topic of chemical kinetics. We'll talk about the different factors that cause chemicals to react with each other. And you'll learn 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. We'll then 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 we'll talk about what can go wrong when an enzyme is missing.
Lesson 09 - Stoichiometry: The Arithmetic of Chemistry
In this lesson, we're going to 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. We'll end the lesson with 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.
Lesson 10 - Solutions
In this lesson, we'll go over some basic information about solutions. We'll start out with a discussion of different types of mixtures, and then we'll spend the rest of the lesson on the topic of solutions, which is 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 you'll 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. We'll also talk about conditions that affect how easy it is to make a solution, and you'll discover the difference between unsaturated and saturated solutions. I'll teach you how to solve some basic concentration problems, and we'll end the lesson with an interesting discussion about water-soluble and fat-soluble vitamins.
Lesson 11 - Acids, Bases, and Salts
In today's lesson, we're going to review chemicals called acids, bases, and salts. You'll learn about their behavior in water and about their unique characteristics. We'll 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 we'll spend some time on that. You'll learn that the pH of fluids in your body must stay within a certain range and what happens when it doesn't. We'll end the lesson with a discussion of several disorders that may occur when the levels of ions get out of balance.
Lesson 12 - Organic Molecules
In our final lesson, we'll go over four types of bioorganic molecules—carbohydrates, lipids, proteins, and nucleic acids. You'll first come to know the difference between inorganic and organic molecules, and you'll find out why the unique structure of carbon atoms makes it possible for millions of different organic molecules to exist. We'll then move on to discuss 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.