Besides being the gateway to understanding the building blocks of life, chemistry is a prerequisite for all kinds of career paths, including that of the pharmacist, chemical engineer, doctor, clinical biochemist, forensic scientist, and toxicologist, to name a few. These helpful textbooks can set anyone on the road to a rewarding profession, or just answer some interesting questions.

Like in many other sciences, atoms are important in chemistry. Atoms are the basic units of matter, and they themselves consist of three things: protons, neutrons, and electrons. Protons carry a positive charge, electrons carry a negative charge, and neutrons have no charge. In the center of an atom lies a collection of protons and neutrons.

Orbiting this nucleus you will find the electron cloud. This is the interesting field where the electrons of an atom exist. New discoveries about the electron cloud are still being made in the modern era. For example, CERN, which is the European Organization for Nuclear Research, recently studied the electron cloud for its implications in experiments using proton colliders. The electron cloud itself is comprised of a number of orbits. The electrons in orbit around the atom are what allow atoms to interact with each other, linking up to create new bonds. A well known example is H2O, which is one oxygen atom linked to two hydrogen atoms. When these atoms connect, water is created. The interaction between atoms is called a bond.

There are a few types of bonds atoms can make, and these have a large effect on the type of compound created. The bonds are either covalent, ionic, or hydrogen bonds. Covalent bonds are very strong and are created when two atoms share electrons. Ionic bonds occur when two oppositely charged ions attract one another, such as the bond between sodium and chloride to make salt. Hydrogen bonds are weak and created by oppositely charged portions of covalent atoms. The classic example is bonds between water molecules.

During these interactions, atoms sometimes gain or lose an electron. This causes the atom to then gain or lose its negative charge. The resulting atom is called an ion. Positive ions occur when an atom loses an electron. This means more protons than electrons exist, and the resulting charge will be positive. When an atom gains an electron, the balance will shift towards having a negative charge. As an interesting note, negative ions have been studied for years for their benefits to the human body. Introducing negative ions into the environment is even associated with lower depression ratings in some people.

The foundation of chemistry, and much of the known universe, is the interplay between these particles and bonds. Atoms form every element on the periodic table, and collections of these atoms create the world around us. As such, understanding the basic unit of chemistry leads to understanding the basic unit of life itself.