1. Which of the following is true about atmospheric pressure? * 1 point A)None B) Atmospheric pressure decreases in a regular way as one progresses from lower to higher altitudes C) Atmospheric pressure increases in a regular way at higher altitudes D) Atmospheric pressure increases when one progresses from troposphere to stratosphere 2. The largest gaseous component of the atmosphere is A) nitrogen B)carbon dioxide C)water vapor D)oxygen 3. Ozone is A) none B) filters harmful UV-radiation in the stratosphere C) desirable in the troposphere D) an undesirable pollutant in the stratosphere. 4.Which of the following characteristics of the atmosphere is crucial in protecting life on earth? A) Production of O2 by plants B) Reducing temperature extremes between day and night. C) Acid-base neutralization reactions taking place in the troposphere 5. Existence of O3 in the troposphere Harmful UV-radiation is blocked by ozone layer in the A) stratosphere B) thermosphere C) mesosphere D) troposphere 6. The high temperature in the thermosphere is due to A) the absorption of intense solar radiation by oxygen molecules (O2). B) the absorption of intense UV-radiation by ozone C) existence of larger concentration of gaseous molecules which can absorb radiant energy than the other layers D) all 7. Free radicals are highly reactive due to the reason that * A. they are free to move in the atmosphere B. the unpaired electron of a free radical has a strong tendency of pairing. C. they contain oxygen and hydrogen atoms which are highly reactive D. a & b 8. Which of the following atmospheric species is not an unstable species? * A. free radicals B. None C. ions having electrically-charged atoms D. Electronically excited molecules

1. Which of the following is true about atmospheric pressure? * 1 point A)None B) Atmospheric pressure decreases in a regular way as one progresses from lower to higher altitudes C) Atmospheric pressure increases in a regular way at higher altitudes D) Atmospheric pressure increases when one progresses from troposphere to stratosphere 2. The largest gaseous component of the atmosphere is A) nitrogen B)carbon dioxide C)water vapor D)oxygen 3. Ozone is A) none B) filters harmful UV-radiation in the stratosphere C) desirable in the troposphere D) an undesirable pollutant in the stratosphere. 4.Which of the following characteristics of the atmosphere is crucial in protecting life on earth? A) Production of O2 by plants B) Reducing temperature extremes between day and night. C) Acid-base neutralization reactions taking place in the troposphere 5. Existence of O3 in the troposphere Harmful UV-radiation is blocked by ozone layer in the A) stratosphere B) thermosphere C) mesosphere D) troposphere 6. The high temperature in the thermosphere is due to A) the absorption of intense solar radiation by oxygen molecules (O2). B) the absorption of intense UV-radiation by ozone C) existence of larger concentration of gaseous molecules which can absorb radiant energy than the other layers D) all 7. Free radicals are highly reactive due to the reason that * A. they are free to move in the atmosphere B. the unpaired electron of a free radical has a strong tendency of pairing. C. they contain oxygen and hydrogen atoms which are highly reactive D. a & b 8. Which of the following atmospheric species is not an unstable species? * A. free radicals B. None C. ions having electrically-charged atoms D. Electronically excited molecules