Page No 229: - Chapter 18 Waste Water Story class 7 ncert solutions Science - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Question 12:

Study the following statements about ozone:

(a) It is essential for breathing of living organisms.

(b) It is used to disinfect water.

(c) It absorbs ultraviolet rays.

(d) Its proportion in air is about 3%.

Which of these statements are correct?

(i) (a), (b) and (c)

(ii) (b) and (c)

(iii) (a) and (d)

(iv) All four

Answer:

(ii) (b) and (c)