Question

multiple choice question
when electrons bind to oxygen at the end of the electron transport chain, ______ is formed.

water
atp
hydrogen
phosphate

Explanation:

In the electron transport chain (a process in cellular respiration, related to Biology), oxygen acts as the final electron acceptor. Electrons, along with protons (hydrogen ions), bind to oxygen. The reaction is \( \ce{O2 + 4e^- + 4H^+ -> 2H2O} \), so water is formed. ATP is produced via chemiosmosis in the ETC but not directly from oxygen - electron binding. Hydrogen is not formed here (protons and electrons combine with oxygen), and phosphate is involved in ATP synthesis, not this reaction.

Answer:

A. water