• # question_answer Consider the following statements: 1. Nearly 99% of the total mass of the atmosphere lies within 30 km of the Earth's surface. 2. The proportion of ozone in the atmosphere increases to maximum at about 60 km from Earth's surface. Which of the statements given above is/are correct? A)  Only 1  B)  Only 2 C)  Both 1 and 2     D)  neither 1 nor 2

[a] The atmosphere has a mass of about $5.15\times 1018\,kg,$three quarters of which is within about 11 km (6.8 mi; 36,000 ft) of the surface. The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space.