Ionic and Covalent Bonding

What We Know: Valance Electrons Valance electrons are the electrons in the highest energy level (outermost shell) 1 2 3 4 5 6 7 8

What We Know: Lewis Dot Shows the valance electrons available for bonding All want to be at lowest energy level (full 8 or lose e–)

What We Know: Bonding Atoms bond with other atoms by transferring or sharing electrons.

Are We Comfortable? Fist to five, how comfortable are you with the two topics I have just shown: Valance Electrons Lewis Dot

Adding a New Terms Electronegativity: the measure of an atom’s ability to attract electrons to itself (In other words: how badly an atom want’s to “hug” or “keep” it’s electrons)

Adding New Terms Electron Affinity: the measure of an atom’s ability to attract extra electrons (In other words, how badly an atom “wants” another electron)

Adding New Terms Ion: an atom whose total number of electrons does not equal the total number of protons (In other words, it has more or less electrons than it should have) This mostly happens when a chemical reaction(breaking and forming of bonds) occurs

Let’s Look At An Example: Cl Low electronegativity High electronegativity Low electron affinity High electron affinity Potassium wants to LOSE and Chlorine wants to GAIN

Let’s Look At An Example: Cl Low electronegativity High electronegativity Low electron affinity High electron affinity Potassium wants to LOSE and Chlorine wants to GAIN

Let’s Look At An Example: – + K Cl Becomes a positive ion (because lost a negatively charged electron) Becomes a negative ion (because gained a negatively charged electron)

Let’s Look At An Example: Cl K + –

Ionic Bonds Ionic Bond: when one atom TRANSFERS it’s electrons to another atom (an uneven “sharing” of electrons) Cl K + – O H

Ionic Bonds Ionic Bond: when one atom TRANSFERS it’s electrons to another atom (an uneven “sharing” of electrons) Occurs between metals and non-metals Creates an ionic compound Cl K + – O H

You Try! Draw the Lewis Dot Structure for each of the following ionic bonds. Then label which has a high electronegativity (and which has a low), and which has a high electron affinity (and which has a low). Then draw the ionic compound, labeling which atom is becomes a negative ion, and which becomes a positive ion when they bond Li + F K + Br Na + I ----- Meeting Notes (9/30/14 13:40) ----- Did one for the class, then had them do the last two on their own. Reviewed answers after.

Adding New Terms Covalent Bonds: when atoms share electrons (evenly) This occurs when non-metals and non-metals bond Creates covalent compounds

Let’s Look At An Example: F F High electronegativity High electronegativity High electron affinity High electron affinity Both Fluorine’s want to GAIN They EQUALLY want that electron…so they SHARE

Let’s Look At An Example F

You Try! N + N Na + Br Mg + O C + O + O (CO2) Determine which of the following will create ionic bonds and which will create covalent bonds – JUST BY LOOKING AT THEIR PLACE ON THE PERIODIC TABLE: N + N Na + Br Mg + O C + O + O (CO2)

You Try! N + N Na + Br Mg + O C + O + O (CO2) Covalent Ionic Ionic Determine which of the following will create ionic bonds and which will create covalent bonds – JUST BY LOOKING AT THEIR PLACE ON THE PERIODIC TABLE: N + N Na + Br Mg + O C + O + O (CO2) Covalent Ionic Ionic Covalent

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