Understanding Matter and Conservation of Mass

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.