The Prefix is Otterbox's least expensive iPhone case. The durable silicone, polycarbonate skeleton build of the OtterBox Prefix is thicker than the Commuter and Reflex, but also the least protective. The Prefix is a one-piece case, meaning that it does not snap in place like the Reflex .
carbon is considered tetravalent because it has four valence electrons the valence electrons are in the outermost shell of the atom and allows carbon to form four bonds to other atoms
Carbon will then have five valence electrons (its four and the one its sharing with fluorine). Covalently sharing two electrons is also known as a single bond.. Carbon will have to form four single bonds with four different fluorine atoms to fill its octet. The result is CF4 or carbon tetrafluoride.