Chemical Formulas: Reading the Code

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 and 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.

Step 2 — Do

Repeat the experiment two more times for accuracy.

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?