When the transfer of electrons takes place towards the attacking reagent, it is +E effect. Eg. Addition of acids to alkenes

When the transfer of electrons takes place waya from the attacking reagent, it is -E effect eg. Addition of cyanide ion to carbonyl compounds

In which is transfer of five electrons takes place ?

The amount of energy released when an electron is added to an isolated gaseous atom to produce a monovalent anion is called electron affinity or first electron affinity or electron gain enthalpy. The first electron is given a negative sign as the addition of an electron to a neutral atom is an exoergic process. The addition of electron to A^(-1) requires energy to overcome the force of repulsion. Thus, the second electron affinity is an endoergic process. The magnitude of electron affinity depends on a number of factors such as (i) atomic size (ii) effective nuclear charge (iii) screening effect (iv) half and fully filled orbitals and (v) shape of orbital. In general, electron affinity increases as the atomic radii decrease in a period. However, there are exceptions when the atoms have stable configurations. In a group, electron affinity decreases as the size increases. However, the members of 3rd period have somewhat higher values than the members in the 2nd period of the same subgroups. Which of the following processes is endoergic in nature ?

(A) Modified wavelength is more than incident wavelength in crompton effect (R) : When photon collides electron, the free electron takes away a part of the energy of the photon. The remaining energy is scattered as photon of decreased frequency (or) as a photon of increased wavelength

The amount of energy released when an electron is added to an isolated gaseous atom to produce a monovalent anion is called electron affinity or first electron affinity or electron gain enthalpy. The first electron is given a negative sign as the addition of an electron to a neutral atom is an exoergic process. The addition of electron to A^(-1) requires energy to overcome the force of repulsion. Thus, the second electron affinity is an endoergic process. The magnitude of electron affinity depends on a number of factors such as (i) atomic size (ii) effective nuclear charge (iii) screening effect (iv) half and fully filled orbitals and (v) shape of orbital. In general, electron affinity increases as the atomic radii decrease in a period. However, there are exceptions when the atoms have stable configurations. In a group, electron affinity decreases as the size increases. However, the members of 3rd period have somewhat higher values than the members in the 2nd period of the same subgroups. Which of the following species has the highest electron affinity?

Electrolysis involves electronation and de-electronation at the respective electodes. Anode electrolytic cell is the electode at which de-electronation takes place whereas at cathod electronation is noticed. If two or more ions of same charge are to be electonated or deelectronate the ion having lasser discharge potential is discharged. Discharge potential of anion refers for EP_(OP)^(@) of E_("RP")^(@) as the case may be. The products formed at either electode is given in terms Faraday's laws of electrolusis i.e. w=(Eit)/(96500) During electrolysis of CuSO_(4(aq)) , the pH of solution becomes

According to molecular orbital theory, atomic orbitals of nearly same energy of different atoms are combined and form molecule. In homodiatomic molecule two atomic orbitals which have wave function psi_(A) and psi_(B) are combined in two ways (psi_(A)pm psi_(B)) . They have two type of electron density, one is bonding [(psi_(A) pm psi_(B))^(2)] where e- density increase between nucleus. Another is antibonding [(psi_(A)pm psi_(B))^(2)] where e^(-) density decreases between nucleus. These molecular orbitals are filled according to Hund, Pauli, afbau principle. Existence of molecule depends on bond order. where bond order = ("Number of bonding "e^(-)"s- number of antibonding "e^(-)s)/(2) lf the molecule have unpaired electron it is paramagnetic otherwise diamagnetic Statement- 1: Removal of two e^(-) from N^(2) , magnetic behaviour does not change while addition of two electrons in O_(2) magnetic behaviour changes. Statement-2: In N_(2) removal of electron talces place from bonding orbital while addition of e^(-) in O_(2) is in antibonding orbital