In any ecosystem, are the point of entry for new energy.

producers

Explanation:

In any ecosystem, producers are the point of entry for new energy. The new energy obtained in an ecosystem is captured by the producers who utilize this energy to produce food. From the producers, energy then flows in the system from to the consumers

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.

not sure if this what   you'r looking for would be percent composition