Carbon 13 I believe.
Never heard of an isotope for boron or nitrogen and I know Carbon 12 is the original form of carbon so.. Yeah
The answer is 0.492 because there are 100 meters in a hectometer, and 49.2/100 is 0.492
Answer : The boiling point of water increases, 
Solution : Given,
Moles of solute (sugar) = 4 moles
Mass of solvent (water) = 1 Kg
i = 1 for sugar
Formula used :
Where,
= elevation in boiling point
= elevation constant
m = molality
= moles of solute (sugar)
= mass of solvent (water)
i = van't Hoff factor
Now put all the given values in this formula, we get the elevation in boiling point of water.
Therefore, the elevation in boiling point of water is
The answer is it tends to be more negative down a group. This is because as you go down the periodic table, the elements have more electron shells in their atoms. This makes the outermost shells less attracted to the nucleus due to their greater distances from the nucleus. Therefore, these shells are less likely to attract electrons (hence lower electron affinity) and are even more likely to lose electrons from their outer electron orbits.
