Molecular Polarity - Mod 2 PDF

Unlocking of unfamiliar wordss 1. ATOM- THE SMALLEST PART OF A SUBSTANCE THAT CANNOT BE BROKEN DOWN CHEMICALLY. 2. MOLECULE-IS A GROUP OF TWO OR MORE ATOMS HELD TOGETHER BY ATTRACTIVE FORCES KNOWN AS CHEMICAL BONDS. EX. H₂O 3. VALENCE ELECTRONS- ELECTRONS IN THE OUTERMOST SHELL O...

Unlocking of unfamiliar wordss 1. ATOM- THE SMALLEST PART OF A SUBSTANCE THAT CANNOT BE BROKEN DOWN CHEMICALLY. 2. MOLECULE-IS A GROUP OF TWO OR MORE ATOMS HELD TOGETHER BY ATTRACTIVE FORCES KNOWN AS CHEMICAL BONDS. EX. H₂O 3. VALENCE ELECTRONS- ELECTRONS IN THE OUTERMOST SHELL OF AN ATOM AND THAT CAN PARTICIPATE IN THE FORMATION OF A CHEMICAL BOND. 4. DIPOLE- A MOLECULE IN WHICH A CONCENTRATION OF POSITIVE ELECTRIC CHARGE IS SEPARATED FROM A CONCENTRATION OF NEGATIVE CHARGE.  MOLECULES OF COMPOUNDS ARE FORMED BY CHEMICAL BONDS. BONDS ARE EITHER IONIC ( WHEN THEY OCCUR BETWEEN A METAL & NONMETAL)OR COVALENT ( WHEN THEY OCCUR BETWEEN NONMETALS). TWO EXTREMES OF THE BONDING.  THERE ARE BONDS LYING IN BETWEEN THE TWO EXTREMES. THEY ARE CALLED POLAR OR POLAR COVALENT BOND  IN PURE COVALENT BOND, NEUTRAL ATOMS SHARE ELECTRONS EQUALLY BETWEEN THEM.  IN A POLAR COVALENT BOND,PARTIALLY CHARGED ATOMS ARE HELD TOGETHER BY UNEQUALLY SHARED ELECTRONS  IONIC BOND, OPPOSITELY CHARGED IONS ARE HELD TOGETHER BY ELECTROSTATIC ATTRACTION.  ELECTRONEGATIVITY, WHICH IS THE ABILITY OF AN ATOM TO DRAW SHARED ELECTRONS TOWARD ITSELF , HAS ONE IMPORTANT ROLE IN THE FOR-  MATION OF MOLECULES. IT DETERMINES THE ELECTRON DENSITY OF THE SHARED ELECTRONS OR THE PLACE WHERE THE ELECTRONS SPEND MOST OF THEIR TIME  THE BOND BETWEEN ATOMS WHOSE DIFFERENCE IN ELECTRONEGATIVITIES IS LESS THAN 0.5 IS CONSIDERED NONPOLAR.  IF THE ELECTRONEGATIVITY DIFFERENCE IS BETWEEN 0.5 AND 2.0, IT IS CONSIDERED POLAR COVALENT.  A MOLECULAR FORMULA-SHOWS THE ACTUAL NUMBER OF ATOMS OF EACH ELEMENT IN A MOLECULE. EX. H₂O COMPOSE OF 2HYDROGEN ATOMS & ONE (1) OXYGEN ATOM.  THE LEWIS FORMULA OR LEWIS STRUCTURE- OF A MOLECULE PROVIDES INFORMATION ABOUT THE RELATIVE LOCATION OF ATOMS, HOW THEY ARE BONDED, AND THE # OF COVALENT BONDS PRESENT. –IT CONSISTS OF DOTS THAT REPRESENT BONDING AND NONBONDING PAIRS OF VALENCE ELECTRONS.  IF THE ELECTRONEGATIVITY DIFFERENCE BETWEEN TWO ATOMS IN A BOND IS 2.0 OR MORE, IT IS GENERALLY CONSIDERED IONIC.  EX. H₂, HF, AND NA  H₂ TWO ATOMS ARE EXACTLY THE SAME.SHARING OF THE ELECTRONS BET THE TWO ARE EQUAL. THE BOND BET THE TWO HYDROHEN ATOMS IS NONPOLAR.  HF MOLECULE, TWO BINDING ATOMS ARE DIFFERENT,SO ELECTRONS ARE NOT SHARED EQUALLY.  F= 4.0, H= 2.1 (4-2.1=1.9) THE ELECTRONS ARE NOT SHARED EQUALLY SO THE BOND IS REFFERED TO AS POLAR COVALENT BOND.  CLASSIFY THE BONDS OF THE FOLLOWING MOLECULES:  1. CO 7. LICL  2. LIH 8. MGCL₂  3. CCL  4. N₂  5. KCL  6.SO₂