What occurs when two dissimilar metals are connected in a corrosive environment?

When two dissimilar metals are connected in a corrosive environment, electrons flow between them due to the electrochemical potential difference that exists between the two metals. This phenomenon is a fundamental principle of galvanic corrosion. The metal with a higher electrochemical potential will lose electrons and corrode more quickly, while the metal with a lower potential will gain electrons and may be protected from corrosion.

This electron flow establishes a galvanic cell where the dissimilar metals act as electrodes immersed in an electrolyte (the corrosive environment), which facilitates the movement of electrons. The degree to which each metal corrodes depends on their relative positions in the galvanic series, which ranks metals according to their susceptibility to corrosion when paired with different metals.

In summary, the correct answer highlights the critical electrochemical interactions that take place when dissimilar metals are connected, which is vital for understanding and preventing corrosion in practical marine applications.