8.5E Lesson

​8.5E Law of Conservation of Mass

Balanced or Not?

Multiple Choice

An experiment calls for a chemical with the formula NH₃. How many atoms of each element are in the formula?

• 0 nitrogen atoms, 3 hydrogen atoms

• 1 nitrogen atom, 1 hydrogen atom

• 1 nitrogen atom, 3 hydrogen atoms

• 3 nitrogen atoms, 3 hydrogen atoms

Multiple Choice

A substance called "cream of tartar" is sometimes used in baking. The formula for cream of tartar is KC₄H₅O₆. What is the total number of atoms shown in the formula?

• 16

• 15

• 6

• 4

Multiple Choice

Frying eggs

• Physical change
• Chemical change

Multiple Choice

Leaves using carbon dioxide to make sugar

• Physical change
• Chemical change

Multiple Choice

A student notices that sugar heated over a flame turns black. How does the student know that a new substance is being formed?

• The sugar melts within the test tube

• The temperature of the test tube increases

• The color of the sugar changes to black

• The mass of the sugar decreases