Chemical and Physical Changes in Matter

What is a key characteristic of a physical change?

• A new substance with different properties is formed.

• The form or state of matter changes, but its molecular structure remains the same.

• The molecular structure of the matter changes.

• Energy is always released as heat or light.

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

• Burning logs in a fireplace.

• Baking bread until golden brown.

• Ice melting into liquid water.

• Metal rusting when exposed to moisture and air.

What happens at the molecular level during a chemical change?

• The original substance transforms into a different substance with new properties.

• The substance changes its form but retains its original molecular structure.

• The state of matter changes from solid to liquid or gas.

• The size and shape of the substance are altered.

Which of these processes represents a chemical change?

• Cutting paper into smaller pieces.

• Iron rusting due to exposure to oxygen and moisture.

• Molding clay into different shapes.

• Preparing a salad by slicing vegetables.

What type of change occurs when iron rusts?

• Physical change

• Chemical change

• State change

• Phase change

When wood burns in a fireplace, what is the primary type of change that occurs?

• Physical transformation

• Chemical reaction

• Melting

• Sublimation

What kind of change takes place when raw ingredients like flour, eggs, and sugar are baked into a cake?

• Physical change, as only the form changes.

• Chemical change, as new compounds are formed.

• State change, from liquid to solid.

• Mixture formation, as ingredients combine.

What indicates that mixing baking soda and vinegar results in a chemical change?

• The mixture becomes colder.

• The mixture changes color.

• The formation of carbon dioxide gas.

• The ingredients dissolve into each other.