Answer: The empirical formula for the given compound is 
Explanation : Given,
Percentage of C = 38.8 %
Percentage of H = 16.2 %
Percentage of N = 45.1 %
Let the mass of compound be 100 g. So, percentages given are taken as mass.
Mass of C = 38.8 g
Mass of H = 16.2 g
Mass of N = 45.4 g
To formulate the empirical formula, we need to follow some steps:
Step 1: Converting the given masses into moles.
Moles of Carbon =
Moles of Hydrogen = 
Moles of Nitrogen = 
Step 2: Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 3.23 moles.
For Carbon = 
For Hydrogen = 
For Oxygen = 
Step 3: Taking the mole ratio as their subscripts.
The ratio of C : H : N = 1 : 5 : 1
Hence, the empirical formula for the given compound is 
1. carbon lies in the 2nd period where silicon in the third period.
2. carbon is a non metal whereas silicon is a metalloid.
3. there are only 3 isotopes of carbon and 23 isotopes of silicon
4. size of silicon atom is larger
5. silicon is heavier than carbon.
The transitions which fall to the lowest principle position release the greatest energies. In this case, this would be the transition from the 5p to the 3s orbital (a Paschen transition).
Hope this helps!
Using IMA is used in Engineering, but there is a simple rhyme I use called IMA Deer. IMA=De/Dr