Chemical Changes

What is an example of a chemical change?

• Burning wood is an example of a chemical change, as it produces ash and smoke.

• Melting ice into water.

• Boiling water to produce steam.

• Dissolving sugar in water.

What is a precipitate?

• A gas that forms during a chemical reaction.

• A solid that forms and settles out of a liquid mixture during a chemical reaction.

• A liquid that evaporates during a chemical reaction.

• A color change that indicates a chemical reaction has occurred.

What is the difference between a mixture and a new substance?

• A mixture is formed through a chemical change, while a new substance is physically combined.

• A mixture contains two or more substances that are chemically combined, while a new substance is formed through a physical change.

• A mixture contains two or more substances that are physically combined, while a new substance is formed through a chemical change.

• A mixture is a single substance, while a new substance contains multiple components.

What is combustion?

• A process where a substance reacts slowly with oxygen, producing heat and light.

• A chemical change that occurs when a substance reacts rapidly with oxygen, producing heat and light.

• A reaction that occurs only in the absence of oxygen, resulting in no heat or light.

• A physical change that involves the mixing of substances without any chemical reaction.

What are signs of a chemical change?

• Color change, temperature change, formation of a gas, and formation of a precipitate.

• Change in shape, increase in size, melting of solids, and boiling of liquids.

• Color change, evaporation of liquids, mixing of substances, and dissolving of solids.

• Formation of bubbles, change in mass, solidification of liquids, and change in taste.

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 metals by melting them down.

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

What is a physical change?

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

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

• A change that occurs only in gases.

• A change that can be reversed easily.

What is an example of a physical change?

• Melting ice

• Burning wood

• Rusting iron

• Cooking an egg

What happens during a chemical reaction?

• Atoms are created and destroyed.

• Bonds between atoms are broken and new bonds are formed, resulting in new substances.

• Only the physical state of substances changes.

• The temperature of the substances remains constant.

What is a chemical equation?

• A symbolic representation of a chemical reaction, showing the reactants and products.

• A numerical representation of a chemical reaction.

• A graphical representation of a chemical reaction.

• A verbal description of a chemical reaction.