The table below gives the average composition of the Earth’s atmosphere (ppm = parts per million). Water vapour is also present in small and variable amounts.

(a) Draw a Lewis structure for N₂O, ensuring that each atom obeys the octet rule. 

(b) Use the VSEPR model to predict the molecular shapes of SO₂, NH₃, N₂O, CH₄ and CO₂. 

(c) Which of the gases in the table are radicals? For each of the gases you have chosen, explain how the radical nature arises. 

(d) O₃ (ozone) is only present in

(e) Draw an MO diagram for the formation of N₂ from two N atoms, using only the valence orbitals. Use the diagram to rationalize why N₂ is chemically very inert. 

(f) What is the relationship between the monoatomic gases in the Earth’s atmosphere?

Transcribed Image Text:

Gas He Ne Ar Kr Xe H₂ N₂ 0₂ Average amount/ppm 5.2 18 9340 1.1 0.09 0.58 780840 209460 Gas CH4 CO CO₂ N₂O NO 03 SO₂ NH3 Average amount/ppm 1.72 0.12 355 0.31 <0.01 0.1-0.01 <10-4 <10-3