Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main201912 Apr 2019Evening ShiftChemistryClassification of Elements and Periodicity in PropertiesActual

In comparison to boron, berylium has:

Options

  1. Agreater nuclear charge and lesser first ionisation enthalpy
  2. Blesser nuclear charge and greater first ionisation enthalpy
  3. Clesser nuclear charge and lesser first ionisation enthalpy.
  4. Dgreater nuclear charge and greater first ionisation enthalpy.

Correct answer

B. lesser nuclear charge and greater first ionisation enthalpy

Step-by-step solution

Electronic configuration of Be = 1 s 2   2 s 2 Electronic configuration of B = 1 s 2   2 s 2   2 p 1 Due to full-filled configuration of Beryllium, it has higher first ionization energy. Effective nuclear charge Z e f f of Be = 4 - σ = 4 - 2 × 0.85 + 0.35 × 1 = 2.05 Z e f f of B = 5 - σ = 5 - 2 × 0.85 + 0.35 × 2 = 2.6 ∴ Z e f f of B > Z e f f of Be

Practice Classification of Elements and Periodicity in Properties on Quantrex Academy →

More from Classification of Elements and Periodicity in Properties

The correct statement(s) regarding the periodic properties of elements is(are) 2026Match List-I with List-II. List-I Electronic configuration of neutral atom (where n=2 ) List-II 1^ st Ionization Energy (kJ mol ⁻¹ ) A. ns^2 I. 2080 B. ns^2np^1 II. 899 C. ns^2np^3 2026In a period, the first ionisation enthalpy of the element at extreme left and the negative electron gain enthalpy of the extreme right element, except noble gases, are respectively 2026Given below are two statements: Statement I: Aluminium is more electropositive than thallium as the standard electrode potential value of E^ _ Al ³⁺/ Al is negative and E^ _ Tl ³⁺/ 2026Given below are two statements : Statement I: The number of pairs among [Al₂O₃, Cr₂O₃] , [Cl₂O₇, Mn₂O₇] , [Na₂O, V₂O₃] and [CO, N₂O] that contain oxides of same nature (acidic, bas 2026Given below are two statements: Statement I: The correct order of electronegativity of fluorine, oxygen and nitrogen is F > O > N . Statement II: The oxidation state of oxygen in O 2026The 1^ st ionization enthalpy for Mg is +737 kJ/mol. The most probable estimated value of the 2^ nd ionization enthalpy of Mg is ______. 2026The electronegativity of a group 13 element 'E' is same as that of Ge (on Pauling scale and upto one decimal point). The CORRECT statements about E³⁺ are A. It can act as a reducin 2026 Full Classification of Elements and Periodicity in Properties list All JEE Main PYQs