An Explanation of Chemical Reactions and the Inflating Balloon Experiment

What Are Atoms and How Do Chemical Reactions Work?

Everything around us—whether it's air, water, or even our own bodies—is made up of tiny building blocks called atoms. An atom is the smallest unit of matter that retains the properties of an element. Each atom consists of three basic parts:

• Protons – positively charged particles found in the center of the atom (the nucleus)

• Neutrons – neutral particles also located in the nucleus

• Electrons – negatively charged particles that orbit the nucleus in energy levels or shells

Atoms of different elements have different numbers of protons. For example, every hydrogen atom has one proton, while every oxygen atom has eight. The arrangement and number of these subatomic particles determine how an atom behaves and reacts with other atoms.

Understanding Chemical Reactions

Atoms do not usually exist alone. They often bond with other atoms to form molecules or compounds. These bonds involve the atom’s valence electrons, which are the electrons in the outermost shell.

A chemical reaction happens when bonds between atoms are broken and new bonds are formed, rearranging the atoms into new substances. The original substances are called reactants, and the new substances formed are called products.

A chemical equation represents this transformation. For instance:

C₂H₄ + 3O₂ → 2CO₂ + 2H₂O

This equation shows how ethylene gas and oxygen react to form carbon dioxide and water. The atoms are not destroyed or created; they are simply rearranged.

How to Balance Chemical Reactions

Chemical equations must follow the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. This means that the number of atoms for each element must be equal on both sides of the equation.

Here’s how we balance an example reaction where iron reacts with oxygen to form rust:

Unbalanced:
_ Fe + O₂ → Fe₂O₃

Step 1: Balance the oxygen. Fe₂O₃ has 3 oxygen atoms. Since O₂ comes in pairs, we need 3 O₂ molecules to make 6 oxygen atoms. So we place a 3 in front of O₂ and a 2 in front of Fe₂O₃:
_ Fe + 3O₂ → 2Fe₂O₃

Step 2: Balance the iron. The right side now has 4 iron atoms (2 Fe₂O₃ molecules × 2 Fe), so we place a 4 in front of Fe on the left:
4Fe + 3O₂ → 2Fe₂O₃

The equation is now balanced: both sides contain 4 iron atoms and 6 oxygen atoms.

Inflated Balloon Experiment

When you mix baking soda and vinegar, something cool happens: A balloon inflates by itself! But how?

When baking soda and vinegar mix, a chemical reaction happens, which means that the baking soda and vinegar change into something new. This reaction creates a gas called carbon dioxide* (CO2**). This gas will rise and fill the balloon, making it inflate!

*Carbon dioxide is the same gas that we breathe out!

**What does CO2 mean?

The “C” stands for the element*** Carbon and the “O” stands for the element Oxygen. The small “2” after the O stands for “2 Oxygens”, forming di-oxide (di means 2).

***An element is a basic building block of all matter, and each element is only made up of one kind of atom. All elements are shown in The Periodic Table of Elements!

• NaHCO3(Baking Soda)

• CH₃COOH (Vinegar)

• CH₃COONa (sodium acetate/Chemical Byproduct)

Reaction: NaHCO₃ + CH₃COOH →CH₃COONa + CO₂ (Carbon Dioxide) + H₂O (Water)

However, one important thing to note is that Chemical reactions must be balanced.

Reactants (Stuff being mixed) → Products (Stuff being made)

***The number of each element needs to add up to be the same between the Reactants and Products!

That is where Balancing Equations takes place.

If you have 4 C’s in the Reactants, you need 4 C’s in the products! So you can multiply each thing to make it completely balanced.