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 ---> H2 making bonds release energy

H2 ---> 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

H2

F2

H20 NH3

CH4

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.

O2

N2

CO2

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

PCl5 SF6

NO2

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 covalent0.4 - 2.0 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