THE MOST ABUNDANT ELEMENTS FOUND IN ORGANISMS ARE H, C, N, O, Na, Mg, P, S, Cl
3 MAYOR TYPES OF BONDING
IONIC
COVALENT
METALLIC
OCTET RULE:Many representative elements attain at least a share of eight electrons in their valence shells when they form compounds.
INTRAMOLECULAR BOND
COMPOUND
VALENCE ELECTRONS
ELECTRONEGATIVITY Measure of the ability of an atom to attract electrons in the context of a chemical bond
Pauling scale and Mulliken scale
Atoms with higher electronegativity values - greater attraction for electrons
The closer the two atoms in their ENs, the more equal their sharing of electrons
NONPOLAR Two atoms with SIMILAR electronegativity values share electrons equally -NONPOLAR COVALENT
POLAR Two atoms with DIFFERENT electronegativity values share electrons unequally -POLAR COVALENT
ATOMS HAVE NO CHARGE
ATOMS HAVE PARTIAL CHARGE
ATOMS HAVE FULL CHARGE
EXAMPLE Na and Cl
Hydrogen H2
Methane CH4
AMMONIA NH3
WATER H2O
Cl2
IONS
ANION IS NEGATIVLY CHARGED
CATION IS POSITIVLY
IONIC COMPOUUNDS ARE OFTEN SALTS/ CRYSTALS
DIPOLE DIPOLE INTERACTIONS These are strong interactions that occur between polar covalent molecules. They are due to the attraction of the +atoms of one molecule to the - atoms of another molecule
