Questions: Absorbency: Which Materials Soak Up Water?

Question 1

You spill water on a wooden table and grab a paper towel to clean it up. Why does the paper towel soak up the water?

• A. The paper towel is magnetic and attracts water
• B. The paper towel has many tiny fibers and spaces that pull water in and hold it
• C. The paper towel heats up the water and turns it to gas
• D. The paper towel is heavier than water, so the water flows upward into it

Answer: (B)

Paper towels are made of many tiny fibers with small gaps between them. Water is pulled into these tiny spaces by a force that draws liquid into narrow gaps. The more spaces and fibers a material has, the more water it can absorb and hold.

Question 2

When a sponge absorbs water, the water is destroyed.

• T. True
• F. False

Answer: False

False. The water is still liquid water — it is just held inside the sponge's many tiny holes and channels. Squeeze the sponge and the water comes right back out. Absorbent materials hold water; they do not destroy it or change it into something else.

Question 3

Why are raincoats made of non-absorbent materials like nylon or plastic instead of cotton?

Model answer: Non-absorbent materials do not soak up rain, so the water rolls off and you stay dry underneath. Cotton would absorb the rain, become heavy and wet, and let moisture reach your skin.

Absorbency would be a terrible property for a raincoat. You want the rain to slide off, not soak in. Non-absorbent materials repel water, keeping it on the outside. This is a good example of choosing materials based on the property the job requires.