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
Because of the constant repulsion due to the electron clouds around the hydrogen atoms of methane the hydrogens end up as far from each other as possible ~ 109Â°. The shape of the methane molecule is therefore a tetrahedron. Carbon has the ability to form 3 types of covalent bonds with itself or other elements. These bonds are the: single covalent bond, the double covalent bond which, shares 4 electrons. triple covalent bond which shares a total of 6 electrons.