From Wikipedia, the free encyclopedia. The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2.It is found in nature in several forms, including quartz and opal. In fact, silica has 17 crystalline forms.he chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2.
Windsor is home to 217,188 people, according to the 2016 census. Windsor's population has grown by three per cent in the past five years, but the city still fell behind the national growth rate, according to data collected during the 2016 census.
Windsor typically has 116 days a year when the minimum temperature is at 0 Â°C or below. The average date for the last frost in spring is April 17. Frost normally returns here on October 30. The frost-free period extends for 195 days on average between the final spring frost and the first fall frost.