 What is an ionic bond?  What was the overall goal of the ionic bond?  What molecules are most likely to form ionic bonds with eachother?

 What do you think an covalent bond is?  Can you think of a picture of a covalent molecule?

What holds the atoms together? What can form a covalent bond with what? How many covalent bonds can form?

 Covalent bond is the bond formed by the sharing of electrons between atoms

 H + H ---> H 2 making bonds release energy  H 2 ---> H + H requires energy to break bonds  Molecular compounds have less energy and are ‘more stable’

 Electrons attract the positively charged nuclei  They screen the positive charges of the nuclei allowing them to be closer than usual

 H 2  F 2  H 2 0  NH 3  CH 4

 A covalent bond is the sharing of electrons between atoms  Forming a covalent bond releases energy, breaking a bond takes energy  Molecular compounds are more stable than their singular components  The shared electron screen the nuclei of the atoms, allowing the atoms to be closer together

 In covalent bonds, electron sharing usually occurs so that atoms attain the electron configuration of noble gases, or in other words, they share electrons to satisfy the octet rule.

 O 2  N 2  CO 2

 Bond dissociation energy- the amount of energy required to break a bond

 A bond where one atom contributes both bonding electrons Ex. CO

 A resonance structure is a structure that occurs when it is possible to draw two or more valid electron dot structures  Ex. 03  The actual bonding is a hybrid or mixture of the resonance structures

 PCl 5  SF 6  NO 2

 The sharing of electrons isn’t always equal.  Electronegativity is the ability of the atom to attract electrons when the atom is in the compound

 Polar bond is a covalent bond where electrons are shared unequally  Nonpolar is a covalent bond where electrons are shared equally  In a polar bond, the more electronegative atom attracts the electron more strongly and gains a slight negative charge  The less electronegative atom has a slight positive charge

0.0 – 0.4 nonpolar covalent polar covalent > 2.0 ionic

 Weaker than ionic or covalent  Van der Waals Forces  Dipole interactions - between polar molecules  Dispersion forces – motion of electrons  Hydrogen bonds – strong attraction between hydrogen and O, F, N  Because hydrogen is ‘special’  Lack of shielding

 Haikus are three line Japanese poems where the first line has five syllables, the second has seven syllables, and the third has five syllables. Write a haiku about how the electrons behave when a covalent compound is formed