Answer Expert Verified. 1) Answer is: the elements of group 17 (or group 7A) in the periodic table release the most energy by gaining an electron. Group 17 (halogens) elements are in group 17: fluorine (F), chlorine (Cl), bromine (Br) and iodine (I).

To summarize the difference between the electron affinity of metals and nonmetals (Figure 1): Metals: Metals like to lose valence electrons to form cations to have a fully stable octet. They absorb energy (endothermic) to lose electrons. The electron affinity of metals is lower than that of nonmetals.

Ionization energy

The elements of the halogen group (Group 17) gain electrons most readily, as can be seen from their large negative electron affinities. This means that more energy is released in the formation of a halide ion than for the anions of any other elements.

If an electron gains energy in an atom then the electron gets excited and forms excited state of an atom. In an atom when electron gains energy the ground state of an atom in which the atom is most stable changes it’s state to exited state in which the atom is less stable than the ground state of atom.

Cl

O

entropy driven

Ca3N2

MgO has smaller ionic radius, hence, it must higher lattice energy.

The other definition says that lattice energy is the reverse process, meaning it is the energy released when gaseous ions bind to form an ionic solid. As implied in the definition, this process will always be exothermic, and thus the value for lattice energy will be negative.

They will have the smallest distance between centres and will have the largest lattice energies. The smallest ions are at the top of the Periodic Table. Mg2+ is smaller than Ca2+ , so MgO has the largest lattice energy.

Technically the lattice energy in KCl is lower because of the larger size of the potassium ion. The difference in melting points for ionic compounds can be explained by the size of the ions themselves; smaller ions are able to get closer, and this increases the strength of the electrostatic charge between them.

Calculate the lattice enthalpy of MgBr2 given that: Enthalpy of formation of MgBr2 = 524 kl mol Sublimation enthalpy of Mg = 148 kJ mollonization enthalpy of Mg=2187k) mol Vapourisation enthalpy of Br2 (1)=31 kJ mol Dissociation enthalpy of Brz (g) = 193 kJ mol Electron gain enthalpy of Br (g)=331 kJ mol?

The lattice energy of magnesium sulfide is -3406 kJ/mol.

NaF shows the highest lattice energy. Smaller the size of cation, more is attraction among ions. The bond between ions of opposite charge is strongest when the ions are small. The lattice energies for the alkali metal halides is therefore highest for NaF.

Conversely, for a given alkali metal ion, the fluoride salt always has the highest lattice energy and the iodide salt the lowest. Lattice energies are highest for substances with small, highly charged ions….Calculating (Ionic) Lattice Energies.

The lattice energies in kcal./mole at 0 K. are computed to be, for Na2S 524.4, for K2S 472.9, and for Rb2S 461.4. These values, in conjunction with known thermodynamic data, have been used to derive the affinity of atomic sulphur for two electrons: E(S –> S~-) = –94.5 2.7 kcal. or –4.10 0.1 e.V. (0 K.).

The magnitude of lattice energy depends on the forces acting on the ions….Lattice Energy & Hydration Energy – Entropy: how far?

Factors Affecting Lattice Energy This model emphasizes two main factors that contribute to the lattice energy of an ionic solid: the charge on the ions, and the radius, or size, of the ions. as the charge of the ions increases, the lattice energy increases. as the size of the ions increases, the lattice energy …

Magnesium ions are smaller than sodium ions, and oxide ions are smaller than chloride ions. That means that the distance between the positive and negative ions is quite a lot less in MgO than in NaCl, and so the forces of attraction will be greater in MgO.