Chapter 2: Composition and Chemistry of Life - Part 1

We shall all wave "good-bye" to my textbook's lovely Introduction and wave "hello" to the next chapter in this scientific tale.

Chapter 2

Chapter 2 is focused mainly around Chemistry (as is hinted in the title), meaning that we will be spending our time in this post learning about the composition of Life's building blocks (atoms and molecules). First, though, we should go over one thing: Matter and Mass. Okay, that's two things.

Matter and Mass

Matter is anything that takes up space in the world, and mass is the amount of matter that that particular thing has. So the more an object takes up space, the more mass it has. The computer you're using to read this has a mass. If you're using a phone to read this: your phone also has a mass, but chances are its mass is a lot less than the computer's (unless you have a really big phone or a really small computer). 

Mass does not equal weight though! The weight of an object depends on the amount of Gravity pushing on that object, where as the mass of an object is the same no matter where it is because the amount of space an object takes up never changes. "Why is this important?" We ask. Let's see.

Atoms and Molecules

All matter (that would mean all objects) are made up of "basic building blocks", meaning atoms. Atoms, when they come together, form the things we see all around us; I guess that makes them the Lego's of Life.

To understand better, an atom is divided into two parts: the Nucleus and the Electron Shell. The Electron Shall is the outside of an atom, while the Nucleus is made up of subatomic parts (that's parts even small then an atom) inside of the shell. The subatomic parts that make up the inside of an atom are called Protons, and Neutrons. Now wait a minute, where are the Electrons? We'll see. First, though, here's a little of what makes up an atom:

• Neutrons - The Neutrons are located at the center of the atom (Nucleus). They have no charge.
• Protons - Protons have a positive charge and are located in the center of the atom (Nucleus).
• Electrons - The Electrons have a negative charge and are located on the outer part of an atom, in the Electron Shell (there are those Electrons, on the outside).

Here we have a diagram of a Carbon atom and can clearly see the positions of  the Protons, Electrons, and Neutrons.

Protons and Neutrons (which make up the Nucleus) are much bigger than Electrons (on a molecular level anyways), and so it makes sense to say that most of an atom's mass is found in the Nucleus. Despite their different sizes, the charges of both the Protons and Electrons are equal. So the negative charge of one Electron is just as big as the positive charge of one Proton. On another note: no matter what type of atom they are a part of, Protons, Neutrons,  and Electrons are always the same.

The Periodic Table of Elements is a system used by Scientists to list the many different types of atoms. We'll use Hydrogen to list the use of each number and symbol in the system (and we've enlarged it so as to avoid the use of magnifying glasses). On the top of each Element in the Periodic Table is the name of the Element. Each Element is given an abbreviation, or symbol, composed of letter(s). These abbreviations are called the Atomic Symbols (in Hydrogen's case, its Atomic Symbol is H). Under the name of the Element, and above the Atomic Symbol is a number (in this case the number 1) which is called the Atomic Number. The Atomic Number lists the number of Protons the Element has. Although atoms are extremely small (and Protons, Electrons, and Neutrons even smaller), they still have a mass just like everything else in the world. The number under the Atomic Symbol is called the Atomic Mass (yes, there are a lot of "Atomics" running around) and the Atomic Mass is, that's right: the amount of mass each Element has.
The amount of mass for each Proton is equal to 1 Atomic Mass unit; a Neutron is slightly more than 1 Atomic Mass; a Proton is very, very small and so have very little Atomic Mass. According to my textbook we will learn much more about this later on (don't we hate that?).

We've gone over the Nucleus part of an atom a bit (Protons and Neutrons), but haven't done much on the second part of an atom; on to the Electron Shell!

Also known as Clouds or Orbitals, the Electron Shell is made up of, wait for it: Electrons (we saw that coming). Electrons orbit around the Nucleus sort of like the way the Planets orbit around the Sun. There are several levels in the Electron Shell, depending on the atom. The Hydrogen atom has only one energy level (or shell), but there are other atoms (such as the Argon atom) that have up to three shells. Each shell is able to hold a certain amount of Electrons. The first shell can hold a maximum of 2 Electrons; the second shell can hold a maximum of 8 Electrons; the third shell can hold a maximum of 18 Electrons; and so forth and so on. Except for in the first level, Electrons travel in pairs as they orbit around the Nucleus.

The Argon atom has 18 Electrons and three shells.

That's all for part 1 *sigh*, now onto part 2.