3.2.1 Define 1st IE and Electronegativity IB Chemistry SL

First ionisation energy is the energy required to remove an electron from a gaseous atom, leaving a gaseous ion. A low 1st I.E. means that the electron comes off easily, a high value means that the electron does not "want" to come off -- so the atom is probably a non-metal.
Electronegativity is a measure of the ability of an atom to attract electrons in a bond. Fluorine has the highest EN -- it loves electrons the most -- very electrophilic. Metals are electrophobic with low EN values.

[juvale]

Very helpfull more people should make videos like your to accompany the IB course!

[ibchemvids]

@FailedVideos Your definition is the molar 1st ionization energy (if you add at the end" leaving 1mole of gaseous monopositive ions")
If you want the "standard" then add "at STP"
From looking at IB past papers - either the molar or non-molar is OK - BUT you must mention gaseous state!

[varun]

Electronegativity: An atom's affinity to attract a shared pair or shared pairs of electrons in the covalent bond of which they are a part. (my teaches gave us this definition; while it seems like a very text book answer, it seems to cover every aspect of electronegativity.)

[ibchemvids]

@FailedVideos My knee jerk reaction is to say that equations are probably the most important thing - but I have thought about it and now I am not so sure...
The IB does not often ask you to write equations since if you mess it up, then you mess up the rest of the question and score poorly - error carried forward may help but then all your math (on the wrong equation) needs to be checked by the grader = long and tedious

[fanChelsea]

Hey, if F has 4.0 electronegativity and hydrogen has 2.1. the difference is 1.9 and that means it is an ionic bond? so does this stil apply? as its not the measure of attraction that an atom has for a SHARED pair of electrons.

[xXxTamaraxXx]

ELECTROPHILE HAHAHAHAHAHAHAHAAHAHAHAHHA! You're such a life-saver. God bless you.

[ibchemvids]

hehe you have found essentially the one exception.

[TuckerWooldridge]

1:00 *atom's (meant to be helpful not annoying)

[RyanNorrington]

when I have children you can have one if you want it