[salâ²mÉnelâ²É]. Etymology: Daniel E. Salmon, American pathologist, 1850-1914. a genus of motile gram-negative rod-shaped bacteria that includes species causing typhoid fever, paratyphoid fever, and some forms of gastroenteritis.ny of various gram-negative, rod-shaped bacteria of the genus Salmonella, many of which are pathogenic, causing food poisoning, typhoid, and paratyphoid fever in humans and other infectious diseases in domestic animals.
This means that, overall, the ratio is two oxygen atoms to each silicon atom, giving the formula SiO 2. Silicon dioxide is very hard. It has a very high melting point (1,610 Â°C) and boiling point (2,230 Â°C), is insoluble in water, and does not conduct electricity.These properties result from the very strong covalent bonds that hold the silicon and oxygen atoms in the giant covalent structure.ilicon dioxide. Much of the silicon and oxygen in the Earth's crust is present as the compound silicon dioxide also known as silica. Silicon dioxide has a giant covalent structure.
In dimeric silicon dioxide there are two oxygen atoms bridging between the silicon atoms with an Si-O-Si angle of 94Â° and bond length of 164.6 pm and the terminal Si-O bond length is 150.2 pm.The Si-O bond length is 148.3 pm, which compares with the length of 161 pm in Î±-quartz.he solubility of silicon dioxide in water strongly depends on its crystalline form and is 3â4 times higher for silica than quartz; as a function of temperature, it peaks at about 340 Â°C.