Covalent Bonding Molecular bonding

2 Non-metals electrostatic attraction (+ and -) between the electrons of one atom and the nucleus of another atoms get close enough to share the electrons and fill the outer orbital

Diatomic Molecules Molecules containing 2 atoms Diatomics end in –gen H 2 O 2 F 2 Br 2 I 2 N 2 Cl 2 P 4 S 8

Multiple Bonds covalent bonds can be single, double or triple each shared pair (2 e-) is a single bond in a covalent the more bonds, the stronger and the closer the atoms become to each other

i.e. N 2 i.e. CO 2 i.e. H 2 O

Differences in electronegativity can be used to describe the nature of the bond Covalent bonds have a relative electronegativity between 0-1.7

Example N 2 CO 2 H 2 O

Difference in Electroneg. Type of BondDescription of Electrons >1.7ionicTransfer bw metal & non Polar covalent e- unequally shared 0-0.4Nonpolar covalent e- shared bw nons 0metallice- move

Non polar Covalent Polar Covalent Ionic Solid Metal

Plot these compounds according to boiling point / melting point from low to high Li-F H-O O-O K (s)

Electronegativity and Bonds if 2 identical atoms bond, they will share the e-s equally if the atoms are not identical, the e-s will not be shared equally

The more electronegative atom will attract the e- with greater force therefore the bond will have a negative end and a positive end (due to the electrons being more near one atom)

Polarity A polar covalent bond is a bond formed between unlike nonmetal atoms with an electronegativity difference of betweem 0.5 and 1.7 Polar implies charge separation (like a magnet)

Dipole One end of the bond is positive, the other end negative More electronegative atom is NEGATIVE

examples H-Cl H 2 O

since the chlorine atoms pulls the e- closer to it, the chlorine end is negative and the hydrogen end is positive

Metallic Bonding

Metallic Bonds Hold pure metals together electrostatic attraction between valence electrons and the positive ions that have formed when the electrons leave

Metallic bonding is the in- between of molecular bonding and ionic bonding positive ions are formed, however electrons are shared

electrons in a metal are free to move this gives metal its conductivity

TO DO TODAY Complete topic 1-3 Working with your LAB GROUP, discuss your plan for your lab tomorrow… Complete your Problem, Hypothesis and a relative materials / procedure list for tomorrow…