Exploring Matter and Its Changes

What are the three main states of matter?

• Solid, Liquid, Plasma

• Solid, Liquid, Gas

• Liquid, Gas, Plasma

• Solid, Gas, Plasma

Answer explanation

The three main states of matter are Solid, Liquid, and Gas. Solids have a fixed shape, liquids take the shape of their container, and gases fill the available space. Plasma is a fourth state but not one of the main three.

Which of the following is a physical change?

• Burning wood

• Melting ice

• Rusting iron

• Baking a cake

Answer explanation

Melting ice is a physical change because it involves a change in state from solid to liquid without altering the chemical composition. In contrast, burning wood, rusting iron, and baking a cake involve chemical changes.

What is a chemical change?

• A change in the state of matter

• A change that creates a new substance

• A change in the size of an object

• A change in the shape of an object

Answer explanation

A chemical change is defined as a process that results in the formation of one or more new substances, distinguishing it from physical changes, which only alter the state, size, or shape of an object.

Which of the following is an example of a mixture?

• Water

• Salt

• Air

• Gold

Answer explanation

Air is a mixture of gases, primarily nitrogen and oxygen, making it a clear example of a mixture. In contrast, water, salt, and gold are pure substances.

What property of matter describes its ability to be stretched into a wire?

• Malleability

• Ductility

• Conductivity

• Solubility

Answer explanation

Ductility is the property of matter that allows it to be stretched into a wire. Unlike malleability, which refers to being shaped into sheets, ductility specifically pertains to elongation without breaking.

Which law states that matter cannot be created or destroyed in a chemical reaction?

• Law of Conservation of Energy

• Law of Conservation of Mass

• Law of Gravity

• Law of Motion

Answer explanation

The Law of Conservation of Mass states that in a chemical reaction, matter is neither created nor destroyed. This principle is fundamental in chemistry, making it the correct choice for the question.

What happens to the particles in a solid when it changes to a liquid?

• They move closer together

• They move farther apart

• They stop moving

• They become charged

Answer explanation

When a solid changes to a liquid, its particles gain energy and move farther apart, allowing them to flow freely. This is why the correct answer is that they move farther apart.

Which of the following is a physical property of matter?

• Flammability

• Reactivity

• Density

• Toxicity

Answer explanation

Density is a physical property of matter that describes how much mass is contained in a given volume. In contrast, flammability, reactivity, and toxicity are chemical properties that involve changes in the substance's chemical structure.

What is the process called when a gas changes into a liquid?

• Evaporation

• Condensation

• Sublimation

• Freezing

Answer explanation

The process when a gas changes into a liquid is called condensation. This occurs when gas molecules lose energy and come together to form a liquid, contrasting with evaporation, which is the transition from liquid to gas.

Which of the following is a chemical change?

• Dissolving sugar in water

• Cutting paper

• Cooking an egg

• Boiling water

Answer explanation

Cooking an egg is a chemical change because it alters the structure of proteins, resulting in a new substance. In contrast, dissolving sugar, cutting paper, and boiling water are physical changes.