Which substance can be decomposed by chemical change? 1)ammonia
2)aluminum
3)magnesium
4)maganese

Explanation:

Decomposition is usually only possible for compounds and of all the options, AMMONIA (Option 1) is the only compound (the other options are elements).

The decomposition of ammonia is a mildly endothermic process, yielding hydrogen and nitrogen gas:

             2NH₃ → N₂ + 3H₂  

h let me think

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.