Correct Answer: Option B) 2 only
The Earth's atmosphere consists of several distinct layers, each with unique characteristics.
Statement 1: "All layers of the atmosphere have well-defined boundaries" - This is Incorrect.
The atmospheric layers do not have sharp, well-defined boundaries. Instead, they transition gradually from one layer to another. The boundaries between layers like the troposphere-stratosphere (tropopause), stratosphere-mesosphere (stratopause), and mesosphere-thermosphere (mesopause) are transition zones rather than distinct lines. The exact altitude of these boundaries can vary with latitude, season, and weather conditions.
Statement 2: "The temperature trend in the atmosphere alternates with each successive layer" - This is correct.
The temperature pattern in the atmosphere shows a clear alternating trend:
Troposphere: Temperature decreases with altitude (gets colder as you go up)
Stratosphere: Temperature increases with altitude (due to ozone absorption of UV radiation)
Mesosphere: Temperature decreases with altitude (coldest temperatures in atmosphere)
Thermosphere: Temperature increases dramatically with altitude (due to absorption of high-energy solar radiation)
