Structure and Properties of Matter

These models represent particles of an element in different physical states.

From left to right, how should these models be labeled to correctly identify their

physical states?

• gas, liquid, solid

• solid, gas, liquid

• iquid, gas, solid

• solid, liquid, gas

Jules thinks that by performing a simple experiment he can show that mass is

conserved. He records his results in the table below

What best represents Jules’ dependent (outcome) variable?

• The amount of ice cubes added to the bowl

• The amount of time the ice cubes took to melt in the bow

• The change in mass as the ice cubes melted in the bowl

• The change in temperature as the ice cubes melted in the bowl

Answer explanation

Dependent variable: It is something that depends on other factors. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it.

Which statement best describes how Jules should present his findings?

• He should say the results are inconclusive.

• He should say the results prove his hypothesis.

• He should say the results support his hypothesis.

• He should say the results fail to support his hypothesis

Which is true about the solubilities of substances tested?

• The solubility of potassium chlorate was least affected by temperature change.

• Potassium iodide has the greatest solubility at any temperature tested.

• At any temperature, potassium nitrate is more soluble than sodium chloride.

• Sodium nitrate is less soluble than potassium nitrate at any of the tested

  temperatures.

A student stated that increasing the temperature of the solvent always allows much

more solute to dissolve. Evaluate the student’s statement based on the test results

in the graph. Is her statement supported?

• No, solubility and temperature are unrelated to each other.

• Yes, solubility increases greatly with increased temperature.

• No, the solubility of some substances is not greatly affected by temperature.

• Yes, substances that are not soluble at low temperatures become soluble at

  higher temperatures

Which figure represents a model of a compound?

• A

• B

• C

• D

Students classify various samples of matter into two groups as shown in the

chart.

Which statement best describes how these samples were classified?

• Group A represents mixtures; Group B represents solutions.

• Group A represents pure substances; Group B represents mixtures

• Group A represents elements; Group B represents compounds.

• Group A represents compounds; Group B represents pure substances.

Which of the substances X, Y, and Z is a pure substance?

• only substance X

• only substance Z

• substances X and Y

• substances Y and Z

Which beaker(s) contain(s) a pure substance?

• Beaker A

• Beaker B

• Beaker C

• Beaker A and B

Which method would be most useful for separating this mixture of two compounds?

• Use a magnet on the sample.

• Mix the sample with water.

• Test to see if the sample is conductive.

• Find the volume and mass of the sample in order to find the density.