Question

Adding electron a neutral gaseous atom usually leads to:
A. Liberation of energy
B. Formation of anion
C. Proton/electron ratio decrease
D. Proton/electron ratio increase

Answer 1

We know that electron gain enthalpy is the electron affinity increases across a period while it decreases down a group. The zero group elements have the lowest electron affinity values. Halogens possess the highest electron affinity in the periodic table. In halogens, chlorine possesses the highest electron affinity in the periodic table.

Complete step by step solution:
Electron affinity is the energy released when an electron is added to a neutral gaseous atom is known as electron affinity. The unit for electron affinity is kilojoules per mole. It depends mainly on two factors. Trend in electron gain enthalpy is the electron affinity increases across a period while it decreases down a group. The zero group elements have the lowest electron affinity values.
If an air like atom is to lose quite, they will be removed one when the opposite, that is, in succession and not at the same time. Truly once the air like atom loses one lepton to make a monovalent ion, the quantity of electrons within the ion decreases by one and these area units are commanded by the nucleus of an ion of larger force.
Therefore, with identical energy, they cannot be removed and additional energy is required to make a powerfulness ion. Within the same manner, energy needed to get rid of the third lepton is predicted to be higher. This clearly shows that electrons are a unit removed in succession or one when the opposite. They are atomic size and nuclear charge, Adding electron a neutral gaseous atom usually leads to:
Liberation of energy. The liberated energy is named electron gain enthalpy.
Formation of anion as the ion acquires negative charge due to the excess of electrons.
Proton/electron ratio decrease. In a neutral atom, the number of electrons is equal to the number of protons. When an electron is added, the number of electrons exceeds the number of protons.
Therefore, the correct answer is option A, B, C i.e. liberation of energy, formation of anion and proton/electron ratio decrease.

Note:
Note that the amount of energy released when an atom in the gaseous state accepts an electron to form an anion. Factors that affect electron affinity are Atomic size and nuclear charge. As atomic radii increases, electron affinity increases. As nuclear charge increases, electron affinity increases. It decreases down a group and increases across a period.