LESSON 1: Basic Chemistry
Atoms & Ions | Chemical Bonding | Water | Acid & Bases | Organic Compounds | Carbohydrates | Lipids | Proteins | Enzymes | Nucleic Acids | ATP

This lesson will introduce you the student to basic chemistry principles. An understanding of this basic information will allow you to learn the more advanced topics in your course lectures.

This lesson focuses on a number of areas related to basic Chemistry. You should review each page in order as they build upon one another. Many of these topics will be review. Others may be new to you. Either way you will learn the fundamentals of chemistry needed in this course.



Atoms are the basic unit of chemistry. They consist of 3 smaller things:

These 3 smaller particles are arranged in a particular way. In the center is the Nucleus where you find the positive Protons and neutral Neutrons.

In orbit around the nucleus are the Electrons. These are found in a series of orbits (depending on the atom) with differing numbers of electrons as seen below.

Image of hydrogen, oxygen  and sodium atoms with proton, electrons and neutrons labeled.

Interaction of Atoms

It's the electrons in orbit around the nucleus that allow one atom to interact with other atoms so they can be linked together.

For example, H2O consists of an Oxygen atom linked to 2 Hydrogen atoms. The linkage or interaction between the electrons of the Hydrogen and Oxygen atoms is called a Chemical Bond. More on these later.

Atoms in the Human Body

The human body is made up of a couple dollars worth of chemicals.

The 12 most useful atoms for you to know about are listed below:


Sometimes atoms gain or lose electrons.  The atom then loses or gains a "negative" charge. These atoms are then called ions.

The following image shows Na losing an electron and Cl gaining an electron


Here are some examples of common ions:
Na+ Sodium
K+ Potassium
Cl- Chloride
Ca+ Calcium
Fe+ Iron
P- Phosphorous