Energy of an electron in the ground state of the hydrogen atom is - 2 .18 × 10 - 18 J . Calculate the ionization enthalpy of atomic hydrogen in terms of J mol ‐ 1 .

The energy of an electron in the ground state of the hydrogen atom is - 2 .18 x 10 - 18 J . Therefore, the energy required to remove that electron from the ground state of the hydrogen atom (Ionization enthalpy) = 2 .18 × 10 - 18 J . Hence, ionization enthalpy of atomic hydrogen in terms of J mol - 1 = 2 .18 × 10 - 18 × N A J mol - 1 = 2 .18 × 10 - 18 × 6 .022 × 10 23 J mol - 1 = 1 .31 × 10 6 Jmol - 1 .

The first ionization enthalpy values ( in KJ mol - 1 ) of group 13 elements are: B Al Ga In Tl 801 577 579 558 589 How would you explain this deviation from the general trend?

Generally, on moving down the group, ionization enthalpy generally decreases due to an increase in the atomic size and shielding. Ionization energy ∝ 1 atomic size Ionization energy ∝ 1 shielding effect Thus, on moving down the group, ionization enthalpy decreases from B to Al . But, Ge has higher ionization enthalpy than Al . Al follows immediately after s ‐ block elements, whereas, Ga follows after d ‐ block elements. The shielding provided by d ‐electrons is not very effective. These electrons do not shield the valence electrons very effectively. As a result, the valence electrons of Ga experience a greater effective nuclear charge than those of Al . Further, moving from Ga to In , the ionization enthalpy decreases due to an increase in the atomic size and shielding. But, on moving from In to Tl , the ionization enthalpy again increases. In the periodic table, Tl follows after 4 f and 5 d electrons, The shielding provided by the electrons in both these orbitals is not very effective. Therefore, the valence electron is held quite strongly by the nucleus. Hence, the ionization energy of Tl is on the higher side.

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Give the relation between electronegativity, ionisation energy and electron affinity according to Mulliken.

Important Questions on Classification of Elements - the Periodic Table

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Science>Chemistry>Classification of Elements - the Periodic Table>Periodic Properties of the Elements in the Modern Table

11, 12, 13, and 14 are the atomic numbers of the elements Na, Mg, Al, and Si respectively. Which element has more atomic radius?

MEDIUM

Science>Chemistry>Classification of Elements - the Periodic Table>Periodic Properties of the Elements in the Modern Table

Imagine and write what type of ion can be formed generally by an atom of element with low ionisation energy, low electron affinity with high atomic size?

MEDIUM

Science>Chemistry>Classification of Elements - the Periodic Table>Periodic Properties of the Elements in the Modern Table

Give a reason for the following.

Ionisation potential increases across a period, from left to right.

MEDIUM

Science>Chemistry>Classification of Elements - the Periodic Table>Periodic Properties of the Elements in the Modern Table

On moving from top to bottom in a group, the values of Ionization energy _____.

EASY

Science>Chemistry>Classification of Elements - the Periodic Table>Periodic Properties of the Elements in the Modern Table

When the first electron gain enthalpy