<span>a. Tall prarie grass burns after being struck by lightning.</span>
Well, if you look at group 1 of the periodic table, you will notice a thrend. All elements in group 1 have 1 valence / outer electron. Then you look at period 2, 3, 4 and so on, you will see that the group number corresponds the number of valence/ outershell electrons. Hence, the group determines the electron(s) on the outershell.
Answer: The partial pressure of
is 1.86 atm
Explanation:
Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as 
The given balanced equilibrium reaction is,

Pressure at eqm. 0.973 atm 0.548atm x atm
The expression for equilibrium constant for this reaction will be,

Now put all the given values in this expression, we get :

By solving the term 'x', we get :
x = 1.86 atm
Thus, the partial pressure of
is 1.86 atm