Half Yearly Class 7 Science Set 1

Time: 3 Hours
Maximum Marks: 80
General Instructions:
(i) The question paper consists of 34 questions divided into four sections: A, B, C, and D.
(ii) All questions are compulsory.
(iii) Section A: Questions 1 to 15 are multiple-choice questions, carrying 1 mark each. Select the most appropriate response.
(iv) Section B: Questions 16 to 22 are very short-answer questions, carrying 2 marks each.
(v) Section C: Questions 23 to 31 are short-answer questions, carrying 4 marks each.
(vi) Section D: Questions 32 to 34 are long-answer questions, carrying 5 marks each.
(vii) Answer the questions in the space provided or on a separate answer sheet as instructed.
(viii) Use of calculators is not permitted.

Syllabus: The half-yearly question paper is framed from the following chapters : The Ever-Evolving World of Science, Exploring Substances: Acidic, Basic, and Neutral, Electricity: Circuits and their Components, The World of Metals and Non-metals,  Changes Around Us: Physical and Chemical, Adolescence: A Stage of Growth and Change.

Section A

Q1. What is the first step in a scientific investigation?  (1 mark)
(a) Making guesses
(b) Observing and asking questions
(c) Ignoring observations
(d) Drawing conclusions

Q2. A substance that turns blue litmus paper red is:  (1 mark)
(a) Basic
(b) Salty
(c) Neutral
(d)  Acidic

Q3. In an electric circuit, the component that provides energy is:  (1 mark)
(a) Switch
(b) Bulb
(c) Battery
(d) Wire

Q4. Which of the following is a non-metal?  (1 mark)
(a) Iron
(b) Sulphur
(c) Aluminium
(d) Copper

Q5. Burning of a candle is an example of:  (1 mark)
(a) Physical change
(b) Chemical change
(c) Reversible change
(d) Temporary change

Q6. Which hormone is responsible for growth spurts during adolescence?  (1 mark)
(a) Insulin
(b) Growth hormone
(c) Adrenaline
(d) Thyroxine

Q7. The reaction between an acid and a base produces:  (1 mark)
(a) Salt and water
(b) Sugar and water
(c) Acid and salt
(d) Base and water

Q8.  In an electric circuit, the lamp glows only when: 
(a) The filament is broken
(b) The circuit is complete
(c) Only one wire is connected
(d) The cell is kept open

Q9. Which non-metal is essential for breathing?  (1 mark)
(a) Carbon
(b) Sulphur
(c) Oxygen
(d) Phosphorus

Q10.Which of the following is a physical change that occurs while burning a candle? (1 mark)
(a) Formation of carbon dioxide
(b) Melting of wax
(c) Burning of the wick
(d) Production of heat and light

Q11. Which of the following is a reversible change?  (1 mark)
(a) Baking a cake
(b) Melting of wax
(c) Rusting of iron
(d) Burning of wood

Q12. The change in voice during adolescence in boys is due to:  (1 mark)
(a) Growth of muscles
(b) Lengthening of vocal cords
(c) Increase in height
(d) Change in diet

Q13. Which material is a good conductor of electricity?  (1 mark)
(a) Rubber
(b) Plastic
(c) Copper
(d) Wood

Q14. An indicator used to identify acids and bases is:  (1 mark)
(a) Sugar solution
(b) Salt solution
(c) Turmeric
(d) Distilled water

Q15. Which of the following is a chemical change?  (1 mark)
(a) Tearing of paper
(b) Cooking of food
(c) Boiling of water
(d) Folding of paper

Section B

Q16. What is meant by a scientific investigation? Give one example.  (2 marks)

Q17. Name two substances that are acidic and two that are basic, found at home.  (2 marks)

Q18. Draw a simple electric circuit diagram showing a battery, bulb, and switch.  (2 marks)

Q19. List one physical property each of a metal and a non-metal.  (2 marks)

Q20. Differentiate between a physical change and a chemical change with one example each.  (2 marks)

Q21. Name two secondary sexual characteristics that appear in girls during adolescence.  (2 marks)

Q22. Why is Aluminium used to make cooking utensils?  (2 marks)

Section C

Q23. Explain how you can use litmus paper to test whether a substance is acidic, basic, or neutral.  (4 marks)

Q24. Explain the structure and working of an incandescent lamp with the help of a neat diagram. Why does the lamp stop glowing when the filament breaks?  (4 marks)

Q25. Define malleability and ductility. Explain why school bells and cooking utensils are made of metals, citing the relevant property in each case.  (4 marks)

Q26. What is rusting? Describe two methods to prevent the rusting of iron.  (4 marks)

Q27. Explain the characteristic changes that distinguish males from females during adolescence, citing two examples for each.  (4 marks)

Q28. Define neutralization. Describe how neutralization is used by farmers to treat soil that is too acidic for plant growth.  (4 marks)

Q29 Explain with the help of a diagram how an electric circuit makes a lamp glow. What will happen if the circuit is not connected properly? (4 marks)

Q30. Why are non-metals important? Give two examples of non-metals and their uses in daily life.  (4 marks)

Q31. What is weathering of rocks? Differentiate between physical and chemical weathering with examples.(4 marks)

Section D

32. (a) Explain the importance of observation in a scientific investigation.  (3 marks)
(b) Describe an activity using a conduction tester to determine if an iron nail is a conductor or an insulator. (2 marks)

33.(a) What is adolescence? Explain the role of hormones in physical changes during this stage.  (3 marks)
(b) Discuss two emotional changes during adolescence and suggest ways to cope with them.  (2 marks)

34. (a) Compare metals and non-metals based on their physical properties (at least four points).  (3 marks)
(b) Explain the process of galvanisation and its role in preventing corrosion.  (2 marks)

You can access the solutions to this Half Yearly here.