In this case, we are going to assume that there are 100 atoms to make things easier.
Let R% be the abundance of n-15. With this in mind, we calculate the abundance of n-14 to be 100%-R%
14.0031*(100-R)% + 15.001 * R%= 14.00674
In this case, we can delete or ignore the % sign since we do not want to carry it around, however, we need to keep in mind that the final answer is in %
14.0031*(100-R) + 15.001 * R= 14.00674
1400.31-14.0031R+15.001R=1400.674
0.9979R=0.364
R=0.3648
Then, the abundance of n-15 is 0.3648%
Answer:
212 degrees F, and 100 degrees C.
Explanation:
If the temperature is held constant (which requires some heat input, since evaporation cools things) the liquid will all evaporate. If the temperature is much above 212 F, the water will boil. That means that it wont just evaporate from the surface but will form vapor bubbles, which then grow, inside the liquid itself. :)