Answer:
The Lewis structures are shown in the figure
Explanation:
The lewis structure will be drawn using following steps
i) we will calculate the total number of valence electrons in the molecule
ii) will assign one bond (two electrons in between two atoms)
iii) then distribute the rest of the valence electrons as lone pair or shared pair based on completion of octet.
The structure of each molecule is given in the figure.
Valence electrons:

V.E = 5 +(2)6-1=16

V.E =5 +(2)6+7=24
1 atm = 760 mm Hg
Where 760 mm is the height of Mercury for 1 atm.
For 0.900 atm,
Height of mercury = 0.900*760 = 684 mm Hg
Answer:
during the process of carbon cycle