15.9994 amu
15.9994
There are approximately (1.6 \times 10^{23}) neon atoms in 300 amu of neon.
An atom with a mass of 15 amu is most likely a nitrogen atom, as the atomic mass of nitrogen is approximately 14.01 amu. This means that the atom may have gained or lost a particle, altering its mass slightly.
15
Write "9" then the forward slash "/" and then "15". Or you can write the 9 above a horizontal line with the 15 below that line.
You write it as 3/15. However, that can be simplified to 1/5.
you do 15 * 15 * 15
15 = quinze
15%
15/100 = 0.15 = 15%
150%
.15