INDIAN GEOGRAPHY

Detailed explanation-1: -Silicon makes up 27.7% of the Earth’s crust by mass and is the second most abundant element (oxygen is the first). It does not occur uncombined in nature but occurs chiefly as the oxide (silica) and as silicates. The oxide includes sand, quartz, rock crystal, amethyst, agate, flint and opal.

Detailed explanation-2: -Silicon makes up 27.7 percent of Earth’s crust; it is the second most abundant element in the crust, being surpassed only by oxygen.

Detailed explanation-3: -Silicon is a light chemical element with metallic and nonmetallic characteristics. Silica, as quartz or quartzite, is used to produce silicon ferroalloys for the iron and steel industries and silicon metal for the aluminum and chemical industries.

Detailed explanation-4: -Detailed Solution. The amount of oxygen in the earth’s crust is 46.6%, silicon 27.7%, aluminum 8.1%and iron 5%.