Ns2 electron configuration
Therefore, metals are said to have lower electron affinities. The reason behind losing their valence electrons is that metals’ nuclei do not have a strong pull on their valence electrons. However, metals are less likely to gain electrons as it is easier to lose their valence electrons and form cations. Example: The first electron affinity of chlorine is -349 kJ mol⁻¹ The energy is needed to gain the electron when an electron is added to a metal element. The first electron affinity is the energy released when 1 mole of gaseous atoms acquire an electron to form 1 mole of gaseous -1 ions. Second Electron Affinity: Positive energy because the energy needed is more than gained.įirst Electron Affinity: The energies are always concerned by the formation of positive ions.
Negative energy because energy is released. The electron affinity is further discussed below: Thus first electron affinities are always negative whereas second electron affinity ( electron to negative ion ) is positive.
The energy is released when an electron is being added to a neutral atom. Hence, given a positive sign whereas energy from an exothermic reaction is negative. Talking about energies, energy from an endothermic reaction is positive. The reaction that releases energy is called an ‘exothermic’ reaction and the reaction in which energy is absorbed is called an ‘endothermic’ reaction. The energy of an atom is stated when an atom loses or gains energy through chemical reactions that cause the loss or gain of electrons. The more negative the electron affinity value, the higher an atom’s affinity for electrons. Electron affinity is defined as the quantitative measurement of the energy change that results from adding a new electron to a neutral atom or molecule in the gaseous state.