Please Do Now (5 min)Review: In your own words, what is the Law of Conservation of

Mass? What does it mean?

New stuff: The pictures below show two different chemical reactions. For each one, write formulas for the element clumps on both sides of the arrow.

Reaction #1 Reaction #2

before afterbefore after

Reaction #1

Reaction #2

Closing (5 min – SILENT)

A 1. Clicker: Which of the following equations is balanced?

B H2O H2 + O2C Mg + 2Cl MgCl2D O2 + C 2COE MgO Mg + O2F 2. Writing: How does balancing equations

show you the Law of Conservation of Matter?