Chemical Changes

What is an example of a chemical change?

• Burning wood, which produces ash and smoke.

• Melting ice into water.

• Dissolving sugar in water.

• Chopping vegetables for a salad.

What is a product in a chemical reaction?

• A substance that is formed as a result of a chemical reaction.

• A substance that is consumed during a chemical reaction.

• A catalyst that speeds up the reaction.

• A mixture of reactants before the reaction occurs.

What is the law of conservation of matter?

• The law of conservation of matter states that matter can be created or destroyed in a chemical reaction.

• The law of conservation of matter states that matter cannot be created or destroyed in a chemical reaction.

• The law of conservation of matter states that matter can change forms but is never lost.

• The law of conservation of matter states that matter is only conserved in physical reactions.

What is a physical change?

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

• A change that affects one or more physical properties of a substance without altering its chemical composition.

• A change that occurs only at high temperatures.

• A change that involves the formation of new substances.

Give an example of a physical change.

• An example of a physical change is making a paper airplane.

• An example of a physical change is burning wood.

• An example of a physical change is dissolving sugar in water.

• An example of a physical change is rusting iron.

What is rusting?

• A process where iron is coated with paint to prevent corrosion.

• A chemical change that occurs when iron reacts with oxygen and moisture, forming iron oxide.

• A method of recycling iron by melting it down.

• A physical change that occurs when iron is exposed to sunlight.

What is dissolution?

• The process of a solute dissolving in a solvent to form a solution.

• The process of a solvent evaporating to leave a solute behind.

• The process of mixing two liquids to create a homogeneous mixture.

• The process of a solid turning into a gas without becoming liquid.

What is a reactant?

• A substance that is produced in a chemical reaction.

• A substance that undergoes a chemical change in a reaction.

• A catalyst that speeds up a chemical reaction.

• A mixture of two or more substances.

What is an example of a chemical reaction?

• Vinegar reacting with baking soda to produce carbon dioxide.

• Water boiling to form steam.

• Salt dissolving in water.

• Iron rusting in the presence of moisture.

What is sublimation?

• Sublimation is the process where a solid changes directly into a gas without becoming a liquid first.

• Sublimation is the process where a gas changes into a liquid.

• Sublimation is the process where a solid melts into a liquid.

• Sublimation is the process where a liquid evaporates into a gas.