Reactants & Products
📘 What It Is
This lesson teaches sixth‑grade students how to identify reactants and products in chemical reactions. Students learn how atoms rearrange, how equations represent reactions, and how to recognize evidence that a chemical reaction has occurred.
The goal is to help students understand that reactants go in, products come out, and atoms are simply rearranged, not created or destroyed.
🎯 Learning Objectives
By the end of the lesson, students will be able to:
✨ Define reactants and products
✨ Identify reactants and products in written reactions
✨ Explain that atoms rearrange during chemical reactions
✨ Recognize evidence of chemical change
✨ Interpret simple chemical equations
✨ Connect reactions to the Law of Conservation of Matter
🧩 What Are Reactants & Products?
🔹 Reactants
The starting substances in a chemical reaction. They are present before the reaction happens.
Examples:
- Vinegar + baking soda
- Hydrogen + oxygen
- Iron + oxygen
🔹 Products
The new substances formed after the reaction. They are present after the reaction happens.
Examples:
- Carbon dioxide gas
- Water
- Rust (iron oxide)
🔄 How Chemical Reactions Work
Chemical reactions happen when atoms rearrange to form new substances.
Important ideas:
- Atoms are not destroyed
- Atoms are not created
- Atoms simply rearrange into new combinations
This connects directly to the Conservation of Matter.
🧪 Evidence of Chemical Reactions
Students look for signs such as:
- Gas production (bubbles)
- Color change
- Temperature change
- Formation of a solid (precipitate)
- Light or sound produced
These clues show that new substances have formed.
🧬 Reading Simple Chemical Equations
Chemical equations show reactants → products.
Example 1: Vinegar + Baking Soda
Example 2: Hydrogen + Oxygen
Reactants: hydrogen, oxygen Product: water
Example 3: Rusting
📖 Comprehensive Passage: How Scientists Describe Reactants and Products
Chemical reactions occur when atoms rearrange to form new substances. The substances that start the reaction are called reactants. They interact, break apart, or combine in new ways. The substances formed after the reaction are called products. Even though the products look different from the reactants, they contain the same atoms, just arranged differently.
For example, when hydrogen reacts with oxygen, the atoms rearrange to form water. The hydrogen and oxygen atoms do not disappear; they simply bond in a new way. Scientists use chemical equations to show this process. The reactants are written on the left side of the arrow, and the products are written on the right side. The arrow shows the direction of the reaction.
Understanding reactants and products helps scientists explain real‑world chemical changes, such as rusting metal, baking bread, or mixing vinegar and baking soda. It also connects to the Law of Conservation of Matter, which states that matter cannot be created or destroyed. The total number of atoms in the reactants must equal the total number of atoms in the products.
📚 Vocabulary
Reactant: A starting substance in a chemical reaction
Product: A new substance formed in a reaction
Chemical Reaction: A process where atoms rearrange to form new substances
Equation: A symbolic way to show reactants and products
Precipitate: A solid formed during a reaction
Gas Production: Bubbles showing a reaction is occurring
🎲 Practice Activities
📝 Activity Worksheet:
Students identify reactants and products in five simple reactions.
🔬 Reaction Lab:
Students mix safe household substances (e.g., vinegar + baking soda) and identify reactants and products.
📊 Equation Sorting:
Students sort cards labeled “reactant” or “product” into correct categories.
🧠 Test Yourself:
Interactive quiz “Reactant or Product?”
🏡 Homework Idea:
Observe a real‑world chemical change (rusting, cooking, burning). Identify the reactants and products.