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NCERT Solutions for Class 5th The World Around Us Chapter 1 A drop of water on plain paper and on waxed paper — Activity 9

Book page 18 Updated on2026-09-19

Q1.
1. Take a piece of paper and put a drop of water on it. Observe.
Answer

What you will see: the drop does not stay round. It spreads out at once into a flat wet patch, sinks into the paper, and makes that spot dark, soft and see-through. If you lift the paper, the wet part sags. If you rub it, it tears easily.

How to do it:

  1. Take a plain, clean sheet of paper — a page from an old notebook is fine.
  2. Dip one finger in water and let one drop fall on the middle of the paper.
  3. Count slowly to ten and watch the drop.
  4. Now touch the wet spot gently and note how the paper feels.
Why it happens: Paper is made of countless tiny fibres pressed together, with tiny gaps between them. Water creeps into those gaps and spreads sideways and downwards. The paper absorbs the water — it soaks it up, the way a cloth or a sponge does.
Q2.
2. Colour the paper with a wax crayon. Now, put a drop of water on it. Do you observe any change?
Answer

Yes — a big change. The drop stays as a round shiny bead on the surface. It does not spread and it does not soak in. If you tilt the paper, the drop rolls off, and the paper underneath is still dry.

How to do it:

  1. Take a fresh piece of the same paper.
  2. Colour a patch about the size of your palm with a wax crayon. Press hard and colour it evenly, leaving no white gaps.
  3. Put one drop of water in the middle of the coloured patch.
  4. Watch it for ten seconds, then tilt the paper slowly.
What I checkPlain paperPaper coloured with wax crayon
Shape of the dropFlattens and spreadsStays a round bead
Does it soak in?Yes, at onceNo
Is the paper wet after?Yes, dark and softNo, still dry
If the paper is tiltedThe wet patch staysThe drop rolls off
Why it happens: The crayon leaves a thin layer of wax on top of the paper. Wax and water do not mix, and wax has no gaps for water to enter. So the wax layer seals the paper — it makes it waterproof, which means water cannot pass through it. With nowhere to spread, the drop pulls itself into the smallest shape it can, a round bead.
Q3.
Write your observation.
Answer

My observation: On plain paper the water drop spread out and soaked in, and the paper became wet and weak. On the paper coloured with a wax crayon the drop stayed round, did not soak in at all, and rolled off when I tilted the paper. The wax made the paper waterproof.

Plain paper → water soaks in
Waxed paper → water stays on top and rolls off
What this teaches us about plants: Many leaves have a natural waxy coating, just like the crayon layer. That coating makes the leaf waterproof and stops too much water from getting inside the plant. This helps the plant stay healthy and keeps it from being damaged. That is why raindrops sit like shining beads on a lotus leaf and roll straight off — look at the picture of the leaf on page 18.
Where else do we use this idea? Raincoats, umbrellas, wax-coated paper for wrapping food, and the polish on a car — all of them keep water out in exactly the same way.
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