WCAS Prep 2025

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Example: Melting an ice cube.

Front

What happens to the total mass during a chemical reaction in a closed container?

Back

The total mass stays the same, as mass is conserved in a closed system.

Front

What adaptation helps a cactus survive in the desert?

Back

Deep roots and water storage tissues help a cactus survive by allowing it to access water and store it for dry periods.

Front

Why does a red apple appear red?

Back

A red apple appears red because it reflects red light and absorbs other colors of light.

Front

What is an adaptation?

Back

An adaptation is a characteristic that enhances an organism's ability to survive and reproduce in its environment. Example: A butterfly changing colors to blend in with its surroundings.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form or appearance of a substance without changing its chemical composition, while a chemical change results in the formation of new substances.

Front

What is mass conservation?

Back

Mass conservation is a principle stating that mass cannot be created or destroyed in a closed system during a chemical reaction.

Front

What role do deep roots play in plant survival?

Back

Deep roots allow plants to access water from deeper soil layers, which is crucial for survival in arid environments.

Front

What is the significance of light reflection in colors?

Back

The color of an object is determined by the wavelengths of light it reflects; for example, a red object reflects red wavelengths and absorbs others.

Front

How do adaptations benefit organisms?

Back

Adaptations improve an organism's chances of survival and reproduction by enabling it to better fit its environment.