Quiz on Pure Substances and Mixtures

What is a pure substance?

• A material made of only one type of particle

• A combination of two or more substances

• A substance that can be separated by physical means

• A mixture that has uniform composition

Which of the following is an example of a compound?

• Oxygen (O₂)

• Water (H₂O)

• Sodium (Na)

• Iron (Fe)

What distinguishes a homogeneous mixture from a heterogeneous mixture?

• Homogeneous mixtures can be separated by filtration

• Homogeneous mixtures have a uniform composition

• Homogeneous mixtures contain only one type of substance

• Homogeneous mixtures are always liquids

Which of the following is a characteristic of heterogeneous mixtures?

• They appear the same throughout

• They can be easily separated into their components

• They consist of only one phase

• They cannot be separated by physical means

Which of the following is NOT a separation technique for mixtures?

• Filtration

• Distillation

• Synthesis

• Chromatography

What is the main difference between an element and a compound?

• Elements are made of two or more types of atoms

• Compounds can be broken down into simpler substances

• Elements can be separated by chemical means

• Compounds are always gases

Which of the following is an example of a homogeneous mixture?

• Salad

• Air

• Sand and salt mixture

• Oil and water

Which of the following is an example of a heterogeneous mixture?

• Vinegar

• Steel

• Salad dressing

• Sugar water

What is the definition of an element?

• A substance that can be broken down into simpler substances

• A pure substance made of only one type of atom

• A mixture of two or more compounds

• A substance that has a variable composition

Which separation technique uses differences in boiling points?

• Filtration

• Distillation

• Evaporation

• Centrifugation