Corrosion of Metals

Study Notes

Corrosion

Iron articles are shiny when new but get coated with a reddish brown powder when left for some time, a process known as rusting.
Corrosion occurs when a metal is attacked by substances around it such as moisture, acids, etc.
Examples of corrosion include the black coating on silver and the green coating on copper.
Corrosion causes damage to metal objects such as car bodies, bridges, iron railings, ships, and more.
Iron corrosion is a serious problem, resulting in enormous annual spending to replace damaged iron.

Rancidity

Fats and oils become rancid when oxidized, changing their smell and taste.
Antioxidants are added to food to prevent oxidation, slowing down the rancidity process.
Keeping food in air-tight containers also helps slow down oxidation.
Manufacturers use techniques like flushing bags with nitrogen to prevent oxidation, such as in chip production.

Life Processes

Life processes are the maintenance functions that occur in living organisms, even when they are not actively doing anything.
These processes are necessary to prevent damage and breakdown and require energy from outside the body.

Nutrition

Energy is obtained from outside the body through food, which is primarily carbon-based.
Nutrition is the process of transferring energy from outside the body to the inside.

Growth and Energy

For growth, additional raw materials are needed from outside the body.
The energy obtained from outside sources needs to be broken down or built up and converted into a uniform source of energy for the body.
Chemical reactions, including oxidising-reducing reactions, are necessary to break down molecules.

Respiration

Respiration is the process of acquiring oxygen from outside the body and using it to break down food sources for cellular needs.

Complexity and Specialization

In multi-cellular organisms, not all cells are in direct contact with the environment, making simple diffusion insufficient.
Specialized tissues develop to perform specific functions, including uptake of food and oxygen, transportation, and excretion.

Transportation

A transportation system is needed to carry food and oxygen from one place to another in the body.
This system also transports waste away from cells to excretory tissues.

Excretion

Excretion is the process of removing waste by-products from the body, which are harmful if not discarded.
Specialized tissues for excretion develop in multi-cellular organisms.

Description

Learn about corrosion, a process where metals react with substances around them, causing damage and resulting in rusting. Explore examples of corrosion on different metals and its impact on various objects.