Molecules and Compounds (Part 2)

What You'll Learn

Molecules form when two or more atoms bond together. A water molecule has two hydrogen atoms bonded to one oxygen atom, written as H₂O.

Key Words

molecular formula
pH

Materials Needed

cups
spoons
food coloring
plastic bottles
balloons

Safety First

Do not taste any materials.
Wear safety goggles when mixing liquids.

Steps

Step 1 — Read

Review the background information on Chemical Reactions before starting.

Step 2 — Do

Mix baking soda and vinegar in a sealed bag. Weigh the bag before and after. Did the mass change? Explain why or why not using the law of conservation of mass.

Step 3 — Observe

Note any unexpected results and think about why they happened.

Step 4 — Record

Share your findings with the class or a partner and discuss what you learned.

Check Your Understanding

Question 1

1 of 3

What is the smallest unit of an element?