Formation of Covalent Compounds (molecules)

- a combination of different element - can be ionic or covalent compound - a combination of different element - can be ionic or covalent compounds covalent ionic

when two NONMETALS come in contact they will share electrons rather than transferring them, ex. O and O

covalent bond forms as a result of sharing of electrons very strong, stronger than ionic bond atoms that are covalently bonded form molecules when two atoms form a covalent bond the sharing of electrons allows each to satisfy the octet rule

Lewis Structures of Molecules shared electrons are shows as a dash pairs of valence electrons surrounding each atom and not involved in bonding are called lone pairs Ex. O2

ex. I2, N2, CO2, H20

The type of bonding a group of atoms experience is dictated by electronegativity: the measure of an atom's ability to attract the pair of electrons it shares with another atom within a covalent bond

increases up and right on periodic table metals have a lower electronegativity then nonmetals, therefore metals lose electrons and nonmetals gain them

atoms of elements with a large electronegativity difference will form IONIC compounds (ex. metal and non-metal, NaCl) atoms of elements with a small electronegativity difference will form COVALENT compounds (ex. non-metal and non-metal, ex. HCl)

- more electronegative goes first compounds Covalent - two non-metals - sharing of electrons - more electronegative goes first - form molecules Ionic - metal and nonmetal - transfer of electrons - cations and anions - form formula units