Can anyone explain to me what Ionisation energy, electron affinity & electronegativity is ? Everytime I try to ask my teacher and get him to explain it to me, he sneaks away !

ionization energy is the energy needed to strip a single electron from an uncharged and isolated atom. there are different ionization energies for the electrons in an atom so the 1st energy is for stripping the first away and the 2nd is for stripping the second (eg. Al to Al+ = first, Al+ to Al2+ = second) the energies are also cumulative so if your want to strip away 2 electrons at one go you need an energy equal to the sum of the first and second ionization energies. affinity is for adding electrons along the same lines. electronegativity is a measure of how much an atom attracts electrons. if it is low it is likely to form a positive ion easily and if it is high it will easily form a negative ion. if to atoms with similar electronegativities bond then it will be a covalent bond.

 

hope this is clear enough. i'm starting to see why he shys away

Can anyone explain to me what Ionisation energy, electron affinity & electronegativity is ? Everytime I try to ask my teacher and get him to explain it to me, he sneaks away !

 

Well here's my input on it.

 

Ionization energy: the energy it takes to remove an electron from an atom (and its influence) so it becomes a free electron. Generally we speak of only the valence electrons (in the outer most shell). The energy needed to remove inner electrons usually goes into the field of particle physics rather than chemistry or materials engineering.

 

Electron Affinity: As mentioned, it is generally the same thing. But noticeably from the literature I have read, affinity is used with materials that have a conduction band. Then the electron affinity would be the potential difference between the conduction band and free space. Commonly seen in semiconductors. The term for it for metals is the metal work function.

 

Electronegativity: How good an element is at attracting electrons. This can help you look into the polar nature of some molecules, and which element will attract electrons more strongly. In any bond, the electrons tend to spend more time towards one of the atoms. It's not perfectly equal and electronegativity quantifies this.

Electronegativity: In any bond' date=' the electrons tend to spend more time towards one of the atoms. It's not perfectly equal and electronegativity quantifies this.[/quote']

 

You mean like water.

water has a dipole moment that is a result of differing electronegativities