The answer is simple, like you are hungry you can pay more to get the food than that of the person who is less hungry, Similarily here the non metals want electrons thus they spend the energy more , or they release the energy. By this they lose the energy. So smaller is the size
chlorine shows exceptionally higher electron gain enthalpy than that of florine.
What is a ”three centre two electron bond”? These are the type of covalent bonds in which overlapping of orbitals of three atoms take place but sharing only two electrons. These type of bonds that are found in electron deficient molecules. for example in case of BF3 , the molecule exists as a dimer that
IN CASE OF TOLUENE the methyl group attached to the ring, increases the electron density at ortho and para positions by resonance without changing anything at the meta position. Thus the attacking reagent directly attacks at the electron rich site , thus the methyl group is ortho directing. you can easily understand the movement of
Electron affinity is the amount of energy change during the addition of an electron to an isolated gaseous atom. It can be positive as well as negative. Negative electron affinity means that the energy is released during the addition of electron. Which is a favorable condition for gaining an electron. But positive value means that