Question

Sodium has an electron affinity of-52.9 kJ/mol, while the electron affinity of magnesium is +40 kJ/mol. 4. a) Which of these elements may, under extreme circumstances, be made into an anion? b) Explain why the electron affinity of magnesium is larger than that of sodium.

Answer 1

of energy that most released anten an extra The amount of energy that has electron's added to the neutral species such as we on atom) is known as electron affinity.. ciken are add an extra electron to the species ( molecule son atom) the enengy is released by the system so this is exothermic proces (ie heat evovled during the the proceen) and according to the thermo- dynamic convention the energy he leaned from the system that means cuork is done by the system sol the value of energy will be negative o Here giren in the question that, Election affinity value of Na (sodium) = -52.948/mon Electroon affinity value of my (magnesium)= +40kJ/mon electron affinity value of Na (sodiums is negative (ore) je energy bealsed by the system and electron affinity value of ng is bonitive (trejie enengy is given to the system to forming magnesium ion. and no "energy (ale get energy from the as heat In the case of forming to sodium anion) 18 given to the sodium atom dubing formation of anion.. cutrich is more favourable propens than forming of ng anion sol From the above dissscussion it is clear that under extreme conditions, sodium (Na) may be made into an anion between sodium and magnesium, 2 The electronic configuration of "ha:- (sodium hare 11 electrom) Photo The au fon by I 2P 35 3p. ie 152 252 206 35' (half field oute most accupied after gaining of one electronie, Olbitan) Na tema- The NG- (sodium anion) have 12 electrom-

and the electronic configuration of Na-. 2 ire 152 25² 26. This is the 35² extra electron ( fullfield le gained by outer the sodirem. mast one. occupied by last eleshoon) In na (sodium) The last electron reside in 35 obbital ie 35' which is half-field configuration and in case of sodium anion (Na-) The outelomost obbital 18 35²i.e sullfield as are know so obghitad can accomodate highest number of electron is two (2) And one we know full field orbitals are more sy srimetric than half-field orbital that leads to higher stability of full-field obbitad more than hats - field stability. So, the sodium has an electron a affinity value negative (-52.9kg/mons. Now for the magnesium The electron electronic configuration of my fave 12 - elector) IS 2s 2p 35 3P The obbital in curich the outeromont electron reside is 35 andie full field. After gaining of one electroon te Mg mg- The Magnesium anion (mga) hare 13-electhens.

The electronic configuration of ing-:-(hare 13 elecinen) e 15² 25² 286.35² a 3pl This is the extra & electron cutick is gained by the magnesium and formed magnesium anion. The last electron curich beside on 3 kare bantially field configubation (as we know Phobbital can accomodate maximum six' number of electron). have tener symmetry than the full field 35²-obbitad in cone of magnesium) and we know higher the symmetry greater cuild be the stability By adding extra 'election to the 3p-crobitan in magnesium on and forming magnesium ion destroy the full field electronic configunatic of the outermost Ebbital (35) 80, The magne-sium ariking to maintain the stable de confA (15225²zp635) batter than forming an anion leading to panitially field configuration (15²282 226 352 3p). So The value of electron-affinity is positive (tre) je energy is needed to forming magnesium anion from magnesium element. As we know positive energy is more than the negative enensy.. And from the above disscussion it is cleaned that election affinity of magnesium is langen. than that of sodium.