8th Grade - Classification of Matter - DOK 2 - 8/19/25

Which of the following is an element?

• Salt (NaCl)

• Iron (Fe)

• Water (H₂O)

• Air

An element is best described as:

• A pure substance made of two or more atoms chemically combined

• A pure substance made of only one type of atom

• A mixture that looks the same throughout

• A substance made of metals and nonmetals

Which example is a compound?

• Oxygen gas (O₂)

• Gold (Au)

• Table sugar (C₁₂H₂₂O₁₁)

• Salad

Tags

NGSS.MS-PS1-1

Compounds differ from mixtures because compounds:

• Can be separated by physical means

• Contain only one type of atom

• Have atoms chemically bonded together

• Are always gases

Which of the following is a homogeneous mixture?

• Sand and salt mixed together

• Trail mix

• Salt water

• Oil and water

A homogeneous mixture is sometimes called a:

• Solution

• Compound

• Element

• Suspension

Which is the best example of a heterogeneous mixture?

• Air

• Salt water

• Vegetable soup

• Brass (copper and zinc alloy)

How can you tell a heterogeneous mixture apart from a homogeneous mixture?

• A heterogeneous mixture looks the same throughout

• A homogeneous mixture has only one type of atom

• The parts of a heterogeneous mixture are visibly different

• A homogeneous mixture cannot be separated

Which of the following is a homogeneous mixture?

• Kool-Aid

• Pizza

• Soil

• Granite

Which of the following is a heterogeneous mixture?

• Salt water

• Milk

• Chocolate chip cookie

• Vinegar