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Piyush365

Asked: October 15, 2026In: Class 9 Science

How are mountain and valley breezes formed? Suppose there are two mountains, one covered with grass and another covered with barren rocks; would the temperature of the two mountain breezes be different? If so, how?

Uneven diurnal heating drives these breezes: daytime slope heating draws warm air up as valley breezes, whereas rapid nighttime cooling sends dense air down as mountain breezes. Barren rock slopes generate colder night breezes. Class 9 Science Exploration Chapter 13 Important ...

Piyush365

Asked: October 15, 2026In: Class 9 Science

Which of the following is primarily responsible for warming of the Earth? (i) Solar radiation is immediately absorbed by carbon dioxide, which then releases it as heat. (ii) The atmosphere’s tiny particles absorb incoming solar radiation, which directly heats the Earth. (iii) The Earth’s surface absorbs solar radiation, which is then re-radiated and trapped by greenhouse gases. (iv) The Earth’s environment is heated only by the solar radiation reflected by the clouds.

The correct option is (iii). Solar radiation penetrates the atmosphere and heats the ground, which then emits infrared radiation that is trapped by atmospheric greenhouse gases, sustaining global surface temperatures. CBSE Class 9 Science Chapter 13 Earth as a System: Energy, ...