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
(1.) The carbon tetrachloride molecule is non-polar. Even though the individual C-Cl bonds are polar (chlorine is more electronegative than carbon), the symmetry of the tetrahedral shape of the molecule means no overall molecular polarity exists, and the molecule is non-polar.