Methane is the simplest organic molecule and is the main component of natural gas.

Methane is made up of a carbon atom bonded to four hydrogen atoms.

The chemical formula for methane is CH₄. Notice that in the formula CH₄ there is a number written lower and smaller after the symbol for hydrogen. This is called a subscript. Subscripts show how many atoms of each element are in a compound. Since there are four hydrogen atoms in the molecule, the subscript 4 follows the symbol for hydrogen. If a symbol in a formula does not have a subscript, the number 1 is understood. In other words, there is only one atom of that element in this compound. So for methane, the ratio is 1 carbon atom to 4 hydrogen atoms.

Another way to model carbon is to use the symbols to draw what is called a skeletal structure of the compound. Below is the skeletal structure of methane.

Source: Skeletal Structure of Methane, Wikimedia Commons

Using the skeletal structure to represent atoms that do not show the 3-dimensional arrangement of the atoms. Molecular model kits can be used to show the 3-dimensional structure of compounds. Models made with molecular model kits are often referred to as ball and stick models. A ball and stick model of methane is shown below.

Source: Adapted From Representations of Methane, Gonzaga University

Notice that the carbon (C) has been replaced with a black ball, and the four hydrogen atoms (H) have been replaced with white balls.

Now, you try building a ball and stick model of ethane. Ethane is an organic compound that is a colorless, odorless gas and is a main component of petroleum and natural gas. The formula for ethane is C₂H₆, and the skeletal structure is as follows:

Source: Ethane skeletal structure, Wikimedia Commons

Next, build a ball and stick model of butane. Butane is an organic compound that is a colorless, odorless gas and is a main component of petroleum and is used as a fuel. The formula for ethane is C₄H₁₀ and the skeletal structure is as follows:

Source: Butane skeletal structure, Wikimedia Commons

Fatty acids make up part of a lipid. They are long chains of carbons and hydrogen with oxygen atoms attached at one end. The flat structure of a fatty acid is shown below.

The double line between the carbon and the oxygen represents a double bond.

Build the ball and stick model of this fatty acid.

The formula for glucose is C₆H₁₂O₆, and the skeletal structure is as follows:

Glucose makes a six-sided structure. Fill in the missing atoms in the ball and stick model of glucose.