When we talk about chemical reactions, there are two basic types you should know: synthesis reactions and decomposition reactions. Let’s look at what makes them different.

Synthesis Reactions:

• What It Is: A synthesis reaction, also called a combination reaction, happens when two or more substances join together to make one new product.

• Simple Formula: You can think of it like this: A + B → AB. Here, A and B are the starting substances that combine to create one new thing.

• Example: A well-known example is when hydrogen gas (H₂) combines with oxygen gas (O₂) to create water (H₂O):
  2H₂ + O₂ → 2H₂O

Decomposition Reactions:

• What It Is: On the other hand, a decomposition reaction occurs when one compound breaks apart into two or more products.

• Simple Formula: It looks like this: AB → A + B. In this case, you start with one compound, and it splits into smaller parts.

• Example: A common example is when water is broken down through a process called electrolysis:
  2H₂O → 2H₂ + O₂

Key Differences:

1. What Happens in the Reaction:

   • Synthesis: You are building something up.
   • Decomposition: You are breaking something down.

2. Number of Starting and Ending Materials:

   • In synthesis, you have several starting substances creating one end product.
   • In decomposition, one starting substance falls apart into multiple products.

By knowing these differences, you’ll feel more confident when you learn about different types of chemical reactions!