Question

What is the chemical formula for silicon dioxide?

Answer 1

The chemical formula for any compound is the representation of the total number of atoms present in that molecule. The chemical formula for covalent compounds is written according to IUPAC rules. Silicon dioxide is a covalent compound that has silicon and oxygen atoms which are non – metals that have almost the same electronegativity.

Complete answer:
A chemical formula for any compound represents the total number of atoms involved in a molecule. While writing the chemical formula for any molecule which is covalent in nature, IUPAC has suggested some rules like the non – metal with a lower group number and at the bottom is written first and then the non – metal which has higher group number and top position in a group. Also the name of the non – metal that is written at the end has a prefix and suffix added. The prefix denotes the number of the preceding atom, like di, tri, etc. and the suffix is the conversion of the end to ‘ide’.
Now, we have been given silicon dioxide. This compound contains silicon and oxygen, which are of the same group 16 in the periodic table. But oxygen is at the top of silicon, so silicon is written first in the formula. The oxygen converts to oxide, and it is dioxide, so 2 oxygen atoms. So the formula becomes $Si{{O}_{2}}$ .
Hence, the chemical formula of silicon dioxide is $Si{{O}_{2}}$.

Note:
The compound $Si{{O}_{2}}$ is a highly covalent molecule with oxygen atoms attaching with silicon through double bonds. The crystalline forms of $Si{{O}_{2}}$ involves an arrangement of various molecules of $Si{{O}_{2}}$ forming a giant covalent structure of silica, where silicon is bonded to 4 other oxygen atoms. These units make up quartz compounds that are used to make glass and other compounds.