Question

Почему CO2- газ, а SiO2- твердое вещество?

Answer 1

Потому что простейшая формула оксида кремния (IV) SO2 аналогична формуле оксида углерода (IV) СO2. Между тем физические свойства их резко отличаются (SiO2 — твердое вещество, CO2 — газ). 
Это различие объясняется строением кристаллических решеток. С02 кристаллизуется в молекулярной решетке, SiO2 — в атомной.
Координационное число атома углерода в твердом СO2 равно 2, а кремния в SiO2 равно 4.

Answer 2

CO2 (carbon dioxide) is a gas, while SiO2 (silicon dioxide) is a solid substance. The difference in their physical states can be explained by the differences in their molecular structures and intermolecular forces.

Molecular Structure:

CO2 consists of one carbon atom bonded to two oxygen atoms in a linear arrangement. The carbon atom forms double bonds with each oxygen atom, resulting in a linear molecule. This linear structure allows the CO2 molecules to move freely and independently of each other, which is characteristic of gases.

On the other hand, SiO2 consists of one silicon atom bonded to two oxygen atoms in a tetrahedral arrangement. Each silicon atom is surrounded by four oxygen atoms, forming a three-dimensional network of covalent bonds. This network structure gives SiO2 its solid state, as the atoms are tightly held together and cannot move freely.

Intermolecular Forces:

Intermolecular forces are the forces of attraction between molecules or atoms. They play a crucial role in determining the physical state of a substance. In the case of CO2, the intermolecular forces are weak London dispersion forces. These forces arise from