Module 15: Classification of Matter

A substance is

• either an element or a compound.

• a mixture of compounds.

• always a compound.

• always an element.

A _____ is a heterogeneous mixture that never settles.

• colloid

• suspension

• compound

• solution

A(n) _______ is a substance in which atoms of two or more elements are combined in a fixed proportion.

• mixture

• molecule

• compound

• ion

A mixture in which different materials can be distinguished easily is called a __________ mixture.

Iron and oxygen react to form rust. If 223 g of iron react with 96 g of oxygen, what is the mass of rust formed?

• 319 kg

• 223 g

• 319 g

• 96 g

A change of one substance to another is a _________ change.

• physical

• chemical

• natural

• artificial

Propane (C₃H₈) is a fuel commonly burned for needs such as home heating and cooking food. When propane burns, it reacts with oxygen (O₂). The products of the reaction are carbon dioxide (CO₂) and water (H₂O). If 44.1 g of propane react completely with 160.0 g of oxygen, 132.0 g of carbon dioxide are formed. What is the mass of the other product, water, formed in this reaction?

A(n) _____ is a material made up of two or more substances that can be separated by physical means.

• mixture

• compound

• element

• substance

Which of the following is an example of physical weathering?

• Flowing water carves erosion channels in a hillside.

• Calcium carbonate in limestone changes to calcium hydrogen carbonate.

• Stalactites precipitate in a cave.

• Acid rain corrodes a monument.

Which of the following is a chemical change?

• Sugar dissolves in a cup of water.

• Water expands as it freezes.

• Glass bends as it is heated.

• Gas burns in an engine.