UNIT 6: MATTER RE-DO REVIEW

The diagram shows a magnet near a pile of particles of iron and sulfur. The magnet attracts the iron, separating it from the mixture.

Based on the diagram, which statement is true?

• The properties of a compound are different from the properties of its elements.

• The elements in a compound keep their own properties.

• The parts of a mixture keep their own properties.

• The properties of a mixture are different from the properties of its parts.

Which of the following is a way in which elements and compounds are DIFFERENT?

• Elements are made of identical atoms, whereas compounds are made of identical molecules.

• A compound contains many different kinds of elements, whereas an element contains many different kinds of atoms.

• Compounds can be broken down by physical changes, but elements cannot.

• Elements are pure substances, but compounds are not.

Dry ice is solid carbon dioxide. At room temperature, it changes directly into a gas. A model of which of the following would describe this change?

• Deposition causes the particles of the carbon dioxide gas to lock into place.

• Sublimation occurs due to an increase in the kinetic energy of the particles

• Freezing occurs due to a decrease in the kinetic energy of the particles.

• Evaporation results in a reduction of the mass of carbon dioxide

Hydrogen gas (H2) can be found in trace amounts in Earth's atmosphere. Which of these statements describes a physical property of hydrogen?

• Hydrogen is found in acids

• Hydrogen reacts with oxygen to form water

• Hydrogen gas is less dense than oxygen gas.

• Hydrogen gas is highly flammable

Gina is preparing a poster to show examples of different types of mixtures. Which of the following sets of examples is correct?

• heterogeneous colloid: gelatin dessert with fruit chunks; homogeneous solution: salt water

• heterogeneous colloid: fog; homogeneous suspension: oil-and-vinegar salad dressing

• homogeneous solution: colored water; homogeneous suspension: sandy water

• heterogeneous solution: salt water; homogeneous solution: brass

What type of substance is always made up of two or more different types of elements joined by chemical bonds?

• element

• mixture

• compound

• molecule

a group of atoms bonded together

• atom

• molecule

• compound

• element

a sample of matter, either a single element or a single compound, that has definite chemical and physical properties

• compound

• pure substance

• mixture

• element

Which of the following is a characteristic of mixtures?

• you can always see the different parts of a mixture

• substances that are mixed together retain their properties

• mixtures can only be in solid and liquid form

• You can only see the different parts of a mixture when it is in a liquid form

What is the role of a solvent?

• it dissolves the solute in a mixture

• it gets dissolved in a mixture

• it helps mix solids together

• it keeps the parts of a mixture separated