Which fertiliser has the greatest percentage of nitrogen by mass?
- Aammonium nitrate, $\text{NH}_4\text{NO}_3$; formula mass is 80
- Bammonium phosphate, $(\text{NH}_4)_3\text{PO}_4$; formula mass is 149
- Cammonium sulfate, $(\text{NH}_4)_2\text{SO}_4$; formula mass is 132
- Dpotassium nitrate, $\text{KNO}_3$; formula mass is 101