The video explores the concepts of matter, physical and chemical changes, and the conservation of mass. It begins with an observation of water evaporation, leading to a discussion on how matter can change states and form mixtures. Physical changes, like dissolving sugar in tea, are explained, followed by chemical changes, such as baking a cake. The video emphasizes that matter and mass are conserved, using practical examples to illustrate this scientific principle.

What happens to the water in the glass over time?

• It disappears completely.

• It changes color.

• It turns into ice.

• It evaporates into the air.

What is a physical change in matter?

• A change that can usually be undone.

• A change that forms a new substance.

• A change that increases mass.

• A change that involves a chemical reaction.

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

• Boiling water.

• Baking a cake.

• Melting ice.

• Dissolving sugar in water.

What are the substances called that are changed during a chemical reaction?

• Reactants

• Products

• Elements

• Catalysts

What is the result of a chemical reaction?

• The mass is lost.

• A new substance is produced.

• The reactants remain unchanged.

• A new element is formed.

What is a clue that a chemical change is occurring?

• The substance freezes.

• The substance melts.

• Gas bubbles are produced.

• The substance changes color.

What does the conservation of mass state?

• Mass is neither created nor destroyed.

• Mass is only lost during chemical reactions.

• Mass can change into energy.

• Mass can be created and destroyed.

What happens to the water molecules when water evaporates?

• They turn into ice.

• They become part of the air.

• They disappear.

• They change into sugar.

What happens to the mass of sugar when it dissolves in water?

• It increases.

• It decreases.

• It remains the same.

• It becomes zero.

How can you prove the conservation of mass with a sugar-water solution?

• By tasting the solution.

• By measuring the mass before and after dissolving.

• By heating the solution.

• By observing the color change.