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What differentiates Ionic and Covalent compounds?

 

Definition / explanation

Ionic Compounds are Salt Crystals

What is electronegativity and why should I care?

 

What is electronegativity and why should I care?

Electronegativity is similar to electron affinity, but electronegativity is a measurement of how much an atom desires another atom's electrons. Electron affinity is how much the atom wants its own electrons, electronegativity is how much the atom wants another atom's electrons. I do not remember how they measure electronegativity, but it is one of the few measurements that does not have units. Fluorine is the most electronegative element given a value of 3.98 or 4 depending on the source you use for your info. In general, electronegativity decreases as you go diagonally across the periodic table toward Francium. To help my students get an idea of what electronegativity can be related to, I would warn them that this may be too much if they have delicate ears, but Francium is unfortunately a slut. It does not take much energy to convince her to get rid of her electrons. She gives them up quite readily and easily. She has a low electronegativity value. Fluorine, on the other hand, is more of a player. Fluorine rakes in the electrons, snags them easily from any source nearby.

Electronegativity is technically used to determine if a bond is ionic or covalent. Within covalent bonds, they are either polar or non-polar. I was going to do an image on polarity and unless I misunderstood the directions for this week's assignment, I may not complete the polarity image until after I submit these pages for a grade. The intermolecular forces lessons utilize the result of polarity so it may be covered in more detail there.

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Chart of electronegativity values

to continue to the second lesson in the series, you can click here or on the Covalent Bond link to the left.

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