Chemical Formulas: Reading the Code (Part 2)

What You'll Learn

Chemical formulas show the types and numbers of atoms in a molecule. CO₂ has one carbon and two oxygen atoms. The subscript tells how many of each atom.

Key Words

physical change
chemical change

Steps

Step 1 — Read

Read the introduction and identify the main idea of this lesson.

Step 2 — Do

Build a model of an atom using craft supplies. Show protons, neutrons, and electrons in the correct arrangement. Label each particle.

Step 3 — Observe

Watch carefully for any changes and note the time.

Step 4 — Record

Create a data table to organize your measurements.

Check Your Understanding

Question 1

1 of 3

What type of substance speeds up a chemical reaction without being used up?