Carbon is the only possible solution in this question for the reason that the chemical formula for glucose is c6h12o6 (6, 12 and 6 underscore) and carbon dioxide is co2. Both of the chemical formula contains carbon that is why that is the main element.
<span>802 mm Hg X 13.5/1 = 10827 mm H2O X (1 cm/10 mm) = 1083 cm H2O = 1.08 X 10^3 cm H2O</span>
Answer : The molal freezing point depression constant of X is 
Explanation : Given,
Mass of urea (solute) = 5.90 g
Mass of X liquid (solvent) = 450.0 g
Molar mass of urea = 60 g/mole
Formula used :

where,
= change in freezing point
= freezing point of solution = 
= freezing point of liquid X= 
i = Van't Hoff factor = 1 (for non-electrolyte)
= molal freezing point depression constant of X = ?
m = molality
Now put all the given values in this formula, we get
![[0.4-(-0.5)]^oC=1\times k_f\times \frac{5.90g\times 1000}{60g/mol\times 450.0g}](https://tex.z-dn.net/?f=%5B0.4-%28-0.5%29%5D%5EoC%3D1%5Ctimes%20k_f%5Ctimes%20%5Cfrac%7B5.90g%5Ctimes%201000%7D%7B60g%2Fmol%5Ctimes%20450.0g%7D)

Therefore, the molal freezing point depression constant of X is 
A. A pacemaker
Hope this helps!
Answer:
D) N-Cl.
Explanation:
The electronegativity of the elements in Group 5 (N. P As and Bi) decreases as we go down the Group so N is the most electronegative and chlorine is less able to draw electrons away from N than from the other elements in Group 5.