It would be Magnesium = 1 atom, Oxygen = 2 atoms, Hydrogen = 2 atoms. It has 5 atoms total. There is 1 magnesium and you multiply each element by the the 2 outside the parenthesis to get 2 oxygen and 2 hydrogen.
Answer:
AFAIK
Explanation:
uric acid is much less toxic than ammonia, hence bigger concentrations of it are tolerated in the body. This means you can excrete it while excreting very little water - beneficial wherever water's not abundant.
There's a tradeoff though, uric acid requires more energy to synthesize than ammonia, so pretty much all fish, say, excrete ammonia rather than uric acid - it's no problem to dilute ammonia since there's no water shortage.