Occurrence of metals and non-metals
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Occurrence of metals and non-metals
Metal and Non-metals of Class 8
OCCURANCE OF METALS AND NON-METALS
The upper surface of Earth’s crust is made of sand and silicates. The most abundant metal in the Earth’s crust is aluminum and the second most abundant metal is iron. The most abundant non – metal in the earth’s crust is oxygen followed by silicon.
Metals are found in the earth’s crust as well as in sea water. With the notable exception of gold which exists as an element, most metals occur naturally as compounds in the form of metal oxides, metal sulphides and metal carbonates. These compounds are called minerals. A mineral is a naturally occurring substance that has a definite composition and crystalline structure.
Non-Metals occur in the free (native) state as well as in combined state.
NCERT solutions for class 8 Science prepared by Physics Wallah will help you to solve your NCERT text book exercise.
| Non-Metal | Free State | Combined State |
| Nitrogen | 78% of air by volume is nitrogen | In living organisms as proteins and in soil as nitrogen compounds |
| Carbon | As graphite, and Diamond |
Metal carbonates, natural gas, petroleum,
proteins, carbohydrates, fats and in air as carbon dioxide |
| Sulphur | Present inside the Earth’s crust | Metal sulphides and metal sulphates |
