Exploring Matter: Changes and Properties

A student observes that a piece of iron left outside has developed a reddish-brown coating over time. Which of the following best explains this observation?

• The iron has undergone a physical change due to exposure to air.

• The iron has undergone a chemical change, forming iron oxide due to rusting.

• The iron has absorbed moisture, causing it to expand.

• The iron has melted due to high temperatures.

Tags

NGSS.MS-PS1-2

Which of the following scenarios best illustrates a chemical change?

• Melting ice to form water.

• Dissolving sugar in water.

• Burning wood to form ash and smoke.

• Cutting a piece of paper into smaller pieces.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student is given a task to identify a pure substance based on its chemical properties. Which of the following properties should the student consider?

• pH and flammability

• Melting point and boiling point.

• Mass and volume.

• Shape and size.

Which of the following is an example of a physical change?

• Baking a cake.

• Rusting of iron.

• Freezing water to form ice.

• Burning gasoline in an engine.

A student observes that a candle burns and produces heat and light. Which evidence supports that a chemical change has occurred?

• The candle wax melts.

• The candle wick becomes shorter.

• The production of heat and light.

• The candle changes shape.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following best describes why a material's flammability is considered a chemical property?

• It involves a change in the material's state.

• It describes the material's ability to conduct electricity.

• It involves a transformation into new substances when burned.

• It is related to the material's density.

A student mixes vinegar and baking soda in a closed container and observes the formation of gas bubbles. What conclusion can be drawn from this observation?

• A physical change has occurred, as the substances are mixed.

• A chemical change has occurred, as new substances are formed.

• The substances have dissolved in each other.

• The temperature of the mixture has decreased.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student observes that a metal object has become dull and has a greenish layer on its surface after being exposed to air and moisture. What type of change has occurred?

• Physical change, as the metal's appearance has changed.

• Chemical change, as a new substance has formed on the metal's surface.

• Physical change, as the metal has expanded.

• Chemical change, as the metal has melted.

Tags

NGSS.MS-PS1-2

Which of the following best explains why the tendency to rust is considered a chemical property of a material?

• It involves a change in the material's color.

• It involves a change in the material's mass.

• It involves a reaction with oxygen to form a new substance.

• It involves a change in the material's temperature.

Tags

NGSS.MS-PS1-2

How do you know a chemical change has occurred?

• A precipitate is formed.

• The shape has changed.

• The state of matter has changed

• Electricity can be conducted through the products.

Tags

NGSS.MS-PS1-2