Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
16 Cards in this Set
- Front
- Back
|
What is corrosion?
|
The chemical or electrochemical deterioration of a material or its properties due to its chemical reaction with the surrounding environment |
|
|
Why does corrosion occur?
|
This chemical reaction occurs because of the tendency of metals to return to their naturally occurring state, usually oxide or sulfide ores |
|
|
What is the most common type of corrosion?
|
Electrochemical corrosion |
|
|
DEFINE: Atom |
The smallest unit of an element, made up of a positively charged nucleus surrounded by a system of negatively charged electrons |
|
|
DEFINE: Electron |
A negatively charged subatomic particle |
|
|
When does an electric current occur? |
When electrons are forced to move through metal conductors |
|
|
Do electrons flow through liquid solutions?
|
Only in the presence of ions |
|
|
DEFINE: Ion |
An atom or group of atoms or molecules which has acquired a net electric charge by gaining or losing electrons |
|
|
What happens when ions are forced to move through liquid solutions?
|
An electric current can occur |
|
|
Can ions move through metal conductors? |
No |
|
|
DEFINE: Electrolyte |
Example: Sea water is an electrolyte: an aqueous solution whose major components are sodium and chloride ions |
|
|
DEFINE: Electrochemistry |
The branch of science concerned with chemical reactions at surfaces in contact with electrolytes |
|
|
TRUE OR FALSE:
|
TRUE |
|
|
What are the four conditions necessary for metal corrosion to occur? |
1. A metal which has a tendency to corrode (the anode) 2. A dissimilar conductive metal (the cathode) 3. A conductive liquid (electrolyte) must connect the anode and cathode 4. Electrical contact between the anode and cathode must exist (usually metal-to-metal) |
|
|
How can corrosion be stopped or slowed?
|
For example: painting a metal surface prevents the electrolyte from connecting the anode and cathode) |
|
|
The corrosion reaction in sea water is accelerated by a factor of what?
|
1000 or more |
