Silicone is a polymer with alternate atoms of silicon and oxygen, and organic groups attached to the silicon. Silicones are resistant to water and oxidation, and are stable to heat. Liquid silicones are used for waterproofing, as polishes and anti-foam agents. Silicone greases are high- and low-temperature lubricants (see lubrication), and resins are used as electrical insulators. Silicone rubbers remain flexible at low temperatures.