ICAS Science 2

Question 1

A student leaves a damp cloth on a windowsill in sunlight. After an hour, the cloth is dry. Which process best explains this?

Accepted Answer

Evaporation

Answer

Evaporation occurs when liquid water absorbs heat energy and changes into water vapor, drying the cloth.

Question 2

Which organ system is primarily responsible for removing carbon dioxide from the human body?

Accepted Answer

Respiratory system

Answer

The respiratory system expels carbon dioxide from the body when we exhale through the lungs.

Question 3

A magnet is brought near a pile of mixed sand and iron filings. What will happen?

Accepted Answer

Only the iron filings are attracted

Answer

Magnets attract ferromagnetic materials like iron, but have no effect on non-magnetic materials like sand.

Question 4

Plants appear green because their leaves mainly:

Accepted Answer

Reflect green light and absorb other wavelengths

Answer

Chlorophyll in plant leaves absorbs red and blue light for photosynthesis and reflects green light, making plants appear green.

Question 5

Which of the following is a chemical change rather than a physical change?

Accepted Answer

Wood burning in a fire

Answer

Burning wood is a chemical change because it produces new substances (ash, carbon dioxide, and water vapor) that cannot easily be reversed.

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