Air Water and Weather (Class 3)

What this worksheet covers

This is a fifteen-question practice worksheet on air, water and weather for Class 3, written to the pattern of the SOF National Science Olympiad (NSO). It carries 21 marks and is designed to be attempted in 40 minutes, split across three sections — Scientific Reasoning, Applying What You Know and Achievers Section. Every question is multiple choice with exactly one correct option, and every one comes with a fully worked solution rather than just an answer key — so a child who gets one wrong can see where the reasoning went astray instead of only learning that it did.

Skills your child practises

• Applied problem-solving on air, water and weather at Class 3 level
• Working accurately against a time limit, as the real paper demands
• Scientific Reasoning questions in the olympiad format
• Applying What You Know questions in the olympiad format
• Achievers Section questions in the olympiad format
• Reading worked solutions to find the step that went wrong

How to use it

1. 1There are 15 questions in this worksheet. All questions are compulsory.
2. 2Each question has four options (A), (B), (C) and (D). Exactly one option is correct.
3. 3Questions 1–12 carry 1 mark each. Questions 13–15 (Achievers Section) carry 3 marks each.
4. 4There is no negative marking. Study every diagram and table carefully.

Sample questions from this worksheet

A preview of what's inside Air Water and Weather (Class 3) — the PDF has the full set, and every question comes with a worked solution like these.

1. 1. Which gas of the air do living things use for breathing?

   • AOxygencorrect
   • BNitrogen
   • CCarbon dioxide
   • DWater vapour
   Solution: Living things take in oxygen to release energy from their food. Air is mostly nitrogen, but that gas is not used in breathing.

2. 2. Wet clothes dry fastest on a day that is _______.

   • AWarm with no breeze
   • BCold, damp and still
   • CCool and rainy
   • DHot, dry and windycorrect
   Solution: Evaporation speeds up when it is hot (particles gain energy), dry (the air can take up more vapour) and windy (the vapour is carried away). A hot, dry, windy day gives all three at once.

3. 3. Consider the following statements.(i) Air has weight and takes up space.(ii) Evaporation takes place only at the boiling point.(iii) Sea water can be made drinkable by evaporating it and collecting the vapour.Which of the statements is/are correct?

   • A(i) and (ii) only
   • B(i) and (iii) onlycorrect
   • C(ii) and (iii) only
   • DAll three
   Solution: Statement (i) is true — an inflated balloon weighs slightly more than an empty one, and air keeps water out of an upturned glass. Statement (ii) is false; a wet floor dries at room temperature, well below boiling point. Statement (iii) is true; the salt is left behind and the collected vapour condenses into pure water. Hence (i) and (iii).