CHEMISTRY January 9, 2015 CHEMICAL BONDS

SCIENCE STARTER Log onto 5 MINUTES

ANNOUNCEMENT LAB ON MONDAY FINAL EXAM ON JANUARY 16 AND 20 NO HOMEWORK ACCEPTED AFTER JANUARY 22, 2015

REVIEW IONIC BOND HAS AN ELECTRONEGATIVITY DIFFERENCE GREATER THAN 2.0 COVALENT BOND HAS AN ELECTRONEGATIVITY LESS THAN 1.7 – TWO TYPES INCLUDE POLAR AND NONPOLAR – ALL ARE POLAR EXCEPT FOR THOSE BELOW 0.5 DIPOLE - DISTRIBUTION OF ELECTRON DENSITY

REVIEW THE HIGHER THE ELECTRONEGATIVITY, THE MORE LIKELY TO ATTRACT THE ELECTRONS THE HIGHER THE ELECTRONEGATIVITY, THE HIGHER THE POLARITY AND THE HIGHER THE DIPOLE

INTERMOLECULAR FORCES FORCES BETWEEN MOLECULES

INTERMOLECULAR FORCES 3 TYPES OF FORCES – DIPOLE-DIPOLE FORCES – HYDROGEN BOND – DISPERSION FORCES

DIPOLE-DIPOLE FORCES PERMANENT FORCES ON A POLAR MOLECULES THAT CAUSES THE ATTRACTION BETWEEN POLAR MOLECULES

HYDROGEN BOND SPECIAL TYPE OF DIPOLE-DIPOLE FORCES VERY STRONG VERSION ONLY OCCURS BETWEEN HYDROGEN AND ONE OF THE FOLLOWING – OXYGEN, NITROGEN, FLUORINE STRONGEST OF THE THREE INTERMOLECULAR FORCES

DISPERSION FORCES EXISTS BETWEEN ALL ATOMS AND MOLECULES ELECTRONS MOVE CONSTANTLY – THUS AT ANY POINT, ONE SIDE IS MORE LIKELY TO HAVE MORE ELECTRONS – THIS CREATE A TEMPORARY DIPOLE THE STRENGTH OF THE DISPERSION FORCES DEPENDS UPON THE SIZE