calculate the molecular weight (mw) of the molecule: Example fertilizer: Nitrate (NO3) 1 Nitrogen = 1 x 14 = 14 3 Oxygen = 3 x 16 = 48 14 + 48 = 62 calculate the % element in the molecule: Example: NO3 = 62 N / NO3 = 14 /62 = 22.5% => 22.5% N […]