Substances and Mixtures Quiz

Which of the following best describes a pure substance?

• A material made up of two or more different elements that are physically combined.

• A material made up of only one type of atom or molecule.

• A mixture of different compounds.

• A solution of various elements.

Which on of the following describes iron filings and sand?

• Mixture

• Compound

• Element

• Atom

A student is given a sample and asked to determine if it is a compound or a mixture. What evidence would best support the conclusion that the sample is a compound?

• The sample can be separated into its components by physical means.

• The sample has a uniform composition throughout.

• The sample consists of two or more substances that retain their individual properties.

• The sample can be broken down into simpler substances by chemical means.

Which of the following scenarios best illustrates the concept of a mixture?

• Iron filings and sulfur being heated to form iron sulfide.

• Salt dissolved in water.

• Carbon dioxide being produced from the combustion of gasoline.

A scientist is tasked with creating a model to demonstrate the differences between elements, compounds, and mixtures. Which of the following should be included in the model to accurately represent these differences?

• Elements and compounds should be shown as having variable compositions.

• Mixtures should be depicted as having fixed ratios of components.

• Compounds should be represented as substances that can be separated by physical means.

• Elements should be shown as pure substances consisting of only one type of atom.