Chemical Changes

What is a chemical change?

• A process that involves the transformation of one or more substances into different substances with new chemical and physical properties.

• A physical change that does not alter the chemical composition of a substance.

• A reaction that only occurs at high temperatures and pressures.

• A process that involves the mixing of two or more substances without any change in their properties.

What is an indicator of a chemical change?

• Color change

• Melting point

• Boiling point

• Density change

What are some common signs of a chemical change?

• A change in color, the production of gas, light, and a change in temperature.

• A change in shape, the production of sound, and a change in mass.

• A change in size, the production of heat, and a change in pressure.

• A change in texture, the production of liquid, and a change in density.

What is a compound?

• A substance formed when two or more elements chemically bond together.

• A mixture of different substances that can be separated by physical means.

• A single element that cannot be broken down into simpler substances.

• A solution where one substance is dissolved in another.

Give an example of a physical change.

• Sugar dissolving in water.

• Iron rusting.

• Wood burning.

• Baking a cake.

What is the process of burning wood classified as?

• Physical change

• Chemical change

• Biological change

• Mechanical change

What is meant by 'changing a substance into a new substance'?

• A process where a substance remains unchanged

• A physical change that does not alter the substance

• A chemical change where the original substance is transformed into one or more different substances

• A method of mixing two substances without changing their properties

What happens during a chemical change?

• Substances combine or break apart to form new substances.

• Substances remain unchanged and retain their properties.

• Substances only change in physical appearance without altering their composition.

• Substances can only be combined but not broken apart.

What is the difference between a physical change and a chemical change?

• A physical change alters the chemical composition of a substance.

• A chemical change does not affect the physical properties of a substance.

• A physical change does not change the chemical composition of a substance, while a chemical change results in the formation of new substances.

• A chemical change can be easily reversed, while a physical change cannot.

What is rusting of iron an example of?

• A physical change

• A chemical change

• A biological change

• A mechanical change