Silicon vs Silica
Silica is a common oxide form of silicon. Silicon is commercially prepared using silica in an electric arc furnace. Both silica and silicon have lattice structures. But silica differs from silicon due to the presence of silicon-oxygen covalent bonding. This accounts for all the different properties between two.
Silicon is the element with atomic number 14, and it is also in the group 14 of the periodic table, just below carbon. It is shown by the symbol Si. Its electron configuration is 1s2 2s2 2p6 3s2 3p2. Silicon can remove four electrons and form a +4 charged cation, or it can share these electrons to form four covalent bonds. Silicon is characterized as a metalloid, because it has both metal and nonmetal properties. Silicon is a hard and inert metalloid solid. The melting point of silicon is 1414 oC, and the boiling point is 3265 oC. Crystal like silicon is very brittle. It exists very rarely as pure silicon in nature. Mainly, it occurs as the oxide or silicate. Since the silicon is protected with an outer oxide layer, it is less susceptible to chemical reactions. High temperatures are needed for it to oxidize. In contrast, silicon reacts with fluorine at room temperature. Silicon does not react with acids, but reacts with concentrated alkalis. There are a lot of industrial uses of silicon. Silicon is a semiconductor: therefore, mainly used in computers and electronic devices.
As stated above, silicon exists as its oxide in nature. Silica is an example for that, with the molecular formula of SiO2 (silicon dioxide). Silica is an abundant mineral in earth crust, and it is in sand, quartz, and many other minerals. Some minerals have pure silica, but in some silica are mixed with other elements. In Silica, the sulfur and oxygen atoms joined by covalent bonds form a huge crystal structure. Each sulfur atom is surrounded by four oxygen atoms (tetrahedrally). Silica doesn’t conduct electricity, because there aren’t any delocalized electrons. Further, it is highly thermo stabilized. Silica has a very high melting point, because a large number of sulfur-oxygen bonds have to be broken in order to melt it. When it is given a very high temperature and cooled at a certain rate, the melted silica will solidify to form glass. Silica doesn’t react with any acid except hydrogen fluoride. Moreover, it is not soluble in water or any organic solvent.
Not only silica is abundant in the earth crust, but it is also present inside our bodies in considerable amounts. Silica is needed for healthy maintenance of bones, cartilages, nails, tendons, teeth, skin, blood vessels, etc. It is naturally present in water, carrot, bread, cornflakes, white rice, banana, raisin, etc. Also, silica is widely used in ceramic, glass and cement industries.
What is the difference between silicon and silica?
- Silicon is a single atom; silica is a molecule, which is an oxide of silicon.
- Silica has a higher melting point than silicon.
- Silicon is a semiconductor, but silica doesn’t conduct electricity.
- Very rarely silicon exists as the pure compound, but silica is very abundant on earth.
- Crystal silicon is very brittle, but crystal silica is hard.