How can you tell the matter is conserved in this reaction?

You basically look at it. Count up the atoms in the graphic or the equation below it.

Explanation:

You probably should've asked in the chemistry thread (though this is kind of like very basic biochemistry).

Left side: 2H₂O₂ means there should be a total of 4 hydrogen and 4 oxygen on both sides of the reaction.

Right side: 2H₂O means there are 4 hydrogen and 2 oxygen. Does that mean matter was not conserved? No! The right side also shows an additional O₂, which totals up to a grand 4 hydrogen and 4 oxygen on the right side.

As you can see, if all of the atoms are present in a balanced equation, you say matter is conserved.

i think its c. amphipod

1. a tropical dry forest carries out more rapid nutrient cycling