Which of the following can upset the balance of an ecosystem? too much water
not enough water
too much light
not enough light
all of the above
none of the above

All of the above.

Explanation:

all four of those situations can cause plants to die and animals with it. Without plants, herbivores will not have food and either die or leave, and without herbivores, carnivores will face the same situation.

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.