Matter Review

Which statement best describes a molecule?

• A molecule is always a group of the same atoms bonded together.

• A molecule is always two or more substances in a mixture.

• A molecule is always two or more atoms bonded together.

• A molecule is always a solution.

The diagram shows atoms and molecules.What is true about the diagram?

• The atoms are made up of three molecules.

• Each molecule is made up of two atoms.

• The atoms are made up of two molecules.

• Each molecule is made up of three atoms.

A student selects three identical beakers and fills each beaker with a different substance (A-C). The student then pours the contents of each beaker onto a flat surface, as shown in the image.What can the student conclude about each substance?

• Substances A and B are solids, and substance C is a liquid.

• Substances A and C are solids, and substance B is a liquid.

• Substance C is a solid, and substances A and B are liquids.

• Substance B is a solid, and substances A and C are liquids.

Emily conducts an experiment to compare the densities of cork and iron with water. She places a piece of cork and a small iron nail in a beaker filled with 100 mL of water, and she records her observations.What can Emily conclude from her experiment?

• The iron nail is more dense than water, and the cork is less dense than water.

• The cork is more dense than water, and the iron nail is less dense than water.

• Both the cork and the iron nail are less dense than water.

• Both the cork and the iron nail are more dense than water.

A student adds 20 g of four different powder samples (W, X, Y, and Z) to different beakers with 300 mL of water and stirs each solution. The student then passes each solution through filter paper. Any residue that is left on the filter paper is dried, weighed, and recorded in a table.Which sample has the greatest solubility in water?

• Sample X

• Sample W

• Sample Y

• Sample Z

The table contains information about metals and nonmetals.A scientist must identify object Y using the information in the table. Is object Y most likely a metal or nonmetal, and why?

• Object Y is most likely a nonmetal because it can conduct electricity.

• Object Y is most likely a nonmetal because it is magnetic.

• Object Y is most likely a metal because it can conduct electricity.

• Object Y is most likely a metal because it is not magnetic.

A student places four same-sized blocks (P, Q, R, and S) made of different materials in a beaker with water. The student observes what happens to each block and makes a list of conclusions. Which conclusions are correct?

• 1 and 2

• 1 and 3

• 2 and 4

• 2 and 3

What causes a leaf to float on top of a lake?

• The leaf is more dense than the water.

• The leaf is less dense than the water.

• The leaf has a small surface area.

• The leaf has a small mass.

A student is designing a boat to carry a marble across a bowl of water. The student observes that a flat rectangle of tin foil floats on the surface of the water and tests the ability of the tin foil to carry a marble, as shown.The student observes that both the marble and tin foil sink. Which design change would most likely help the tin foil boat carry the marble?

• Crumple the tin foil to make it round to match the shape of the marble.

• Fold the edges of the tin foil up to keep water off the top surface of the tin foil.

• Use a pen to mark the middle of the tin foil to place the marble accurately.

• Use a smaller piece of tin foil to decrease the amount of water on the surface of the tin foil.

A student designs a boat to carry different numbers of coins across water in a pool. What is the student likely testing?

• density of water

• density of coins

• ability of the boat to float

• ability of the coins to float