Ch 7: Praxis Biology: Molecular Structure Basics

About This Chapter

This chapter can help you understand the structure of a molecule. With these video lessons and quizzes, you can learn about atoms, the electron shell and covalent bonds as you prepare for the Praxis Biology test.

Praxis Biology: Molecular Structure Basics - Chapter Summary

The lessons in this chapter help you explain the structure of molecules and include a look at the atom and its parts. You will learn about various types of chemical bonds. Another lesson explores the properties of water, such as cohesion and high specific heat. By the end of this chapter, you should be prepared to answer Praxis exam questions concerning these topics:

  • The electron shell
  • Chemical bonds: covalent, ionic, polar covalent and hydrogen
  • Solutions, solutes and solvents
  • Osmosis, diffusion and saturation
  • Acids and bases
  • The laws of thermodynamics

Experienced instructors teach these lessons, using examples to illustrate many topics. With these concise, fun lessons, you will gain the information you need to correctly answer the questions on the Praxis Biology exam. The quizzes at the end of each lesson enable you to test your knowledge, and the links included in the videos enable you to easily locate and re-watch key points in the lessons.

Objectives of the Praxis Biology: Molecular Structure Basics Chapter

Many states mandate that applicants for teacher certification pass the Praxis examination in the subject they wish to teach. The Praxis Biology: Content Knowledge exam contains 150 multiple-choice questions that cover what a teacher of biology at the secondary school level should know. The test has a two-hour time limit and is available on paper or computer. It has six sections, and questions on the material contained in the Molecular Structure Basic chapter are in section II, Molecular and Cellular Biology. This section, with 38 questions, makes up about 25% of the total test.

11 Lessons in Chapter 7: Praxis Biology: Molecular Structure Basics
Test your knowledge with a 30-question chapter practice test
The Atom

1. The Atom

Tune into this lesson to find out what matters about matter. What exactly is an atom? And, how do the atoms that make up the elements in the periodic table differ from one another?

The Electron Shell

2. The Electron Shell

You may be familiar with the role of electrons in electrical devices, but did you know that electrons also determine the chemical reactivity of everything around you?

Chemical Bonds I: Covalent

3. Chemical Bonds I: Covalent

Mom always said that sharing is caring. This lesson will explore how electrons affect the chemical reactivity of atoms and specifically the merits of sharing electrons.

Chemical Bonds II: Ionic

4. Chemical Bonds II: Ionic

Did you know that the scientific name for table salt is sodium chloride? Find out how sodium and chlorine atoms come together to form your favorite seasoning.

Chemical Bonds III: Polar Covalent

5. Chemical Bonds III: Polar Covalent

Are you confused about how you can tell what kind of bond two atoms will form? This lesson will help you understand the difference between polar and nonpolar covalent bonds as well as how to predict how two atoms will interact.

Chemical Bonds IV: Hydrogen

6. Chemical Bonds IV: Hydrogen

This lesson defines and discusses important concepts behind hydrogen bonding. You'll learn when and why these bonds occur and which atoms are often involved.

Properties of Water

7. Properties of Water

Why does ice float? Why can water rise on its own against gravity in a small tube? Find out how these mysterious properties of water can be explained by hydrogen bonds.

Solutions, Solutes, and Solvents

8. Solutions, Solutes, and Solvents

Oh no! Your friend Ben just drank chili oil on a dare, and now his mouth is burning. Should he drink the ice water or vegetable oil to cool his mouth? Quick. Watch this lesson if you aren't sure.

Osmosis, Diffusion and Saturation

9. Osmosis, Diffusion and Saturation

The cells in our bodies are in constant flux through the processes of osmosis and diffusion. Learn about how saturation levels force change, and why we're lucky they do.

Acids and Bases

10. Acids and Bases

Have you ever wondered how we measure the acidity of liquids? Check out this lesson to see how acids and bases are measured on a pH scale and how they relate to neutral solutions, such as water.

The Laws of Thermodynamics

11. The Laws of Thermodynamics

Learn about the first and second laws of thermodynamics. Find out how energy is generated, how it converts from one form to another, and what happens to energy in a closed system.

Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
Not Taken
Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
Not Taken

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