Hello Jaswin,

The answer to this problem lies in the simple unitary method followed by a division.

Considering 100g of caffeine, the content of nitrogen is 28.9g.

Now, 100g of caffeine contains 28.9g of Nitrogen

1g of caffeine contains 28.9/100 g of Nitrogen

therefore 194g of caffeine contains (28.9/100)*194 = 56.06g of Nitrogen.

Dividing the weight of Nitrogen present with the atomic weight of Nitrogen, i.e 14, 56.06/14, we get approximately 4.

Therefore 4 atoms of Nitrogen is present in 194g of caffeine.