Definition
A list of metals arranged in order of how readily they give up electrons in a chemical reaction. Metals higher on the list are more chemically active and tend to corrode more easily, while those lower on the list are more stable. When two dissimilar metals from the series are placed in contact in the presence of an electrolyte (such as moisture or salt water), an electrical current flows between them and the more active metal corrodes.
Plain English
A ranked list of metals showing which ones react more easily and which ones resist reacting. When two different metals from this list touch with moisture between them, the more reactive one slowly eats away.
Context Anchor
Seen in aircraft maintenance, corrosion prevention, structural repair, and battery or electrical-system discussions.
Derivation
From Greek 'elektron' (amber, the original source of static electricity) plus 'chemical.' The word reflects that the ranking is based on each metal's electrical and chemical behavior together — how strongly it pushes or releases electrons.
Why Pilots Care
Dissimilar-metal corrosion is a real maintenance concern on aircraft. Knowing that certain metal pairings (like steel fasteners in aluminum skin) will corrode when wet helps explain why protective coatings, sealants, and proper hardware choices matter for airworthiness.
Grounding Statement
If two different metals on an aircraft are connected and salty moisture reaches them, the electrochemical series helps show which metal is more likely to be eaten away first.
Intuition Check
Do not read “series” as a set of maintenance steps. Here it means a ranked list of materials based on how they react electrically and chemically.
Example Sentence 1
The mechanic referenced the electrochemical series to confirm that the steel bolt would accelerate corrosion of the surrounding aluminum if left unsealed.
Example Sentence 2
Knowing the order in the electrochemical series helped the technician choose compatible materials for the battery compartment hardware.