Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 201912 AprilEvening Shift
Exam
JEE Main
Year
2019
Date
12 April
Shift
Evening Shift
Subject
Chemistry
Chapter
Classification of Elements and Periodicity in Properties

JEE Main 2019 · 12 April · Evening Shift · Chemistry · Classification of Elements and Periodicity in Properties

In comparison to boron, berylium has:

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 =1s22s2= 1{s}^{2}2{s}^{2}
Electronic configuration of B =1s22s22p1= 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
Zeff{Z}_{eff} of Be =4−σ=4−(2×0.85+0.35×1)=2.05= 4 - \sigma = 4 - \left(2 \times 0.85 + 0.35 \times 1\right) = 2.05
Zeff{Z}_{eff} of B =5−σ=5−(2×0.85+0.35×2)=2.6= 5 - \sigma = 5 - \left(2 \times 0.85 + 0.35 \times 2\right) = 2.6
∴Zeff∴ {Z}_{eff} of B > Zeff{Z}_{eff} 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) JEE Advanced 2026Match List-I with List-II. List-I Electronic configuration of neutral atom (where n=2 )… JEE Main 2026In a period, the first ionisation enthalpy of the element at extreme left and the… JEE Main 2026Given below are two statements: Statement I: Aluminium is more electropositive than… JEE Main 2026Given below are two statements : Statement I: The number of pairs among [Al_2O_3… JEE Main 2026Given below are two statements: Statement I: The correct order of electronegativity of… JEE Main 2026The 1^ st ionization enthalpy for Mg is +737 kJ/mol. The most probable estimated value of… JEE Main 2026The electronegativity of a group 13 element 'E' is same as that of Ge (on Pauling scale… JEE Main 2026 Full Classification of Elements and Periodicity in Properties list All JEE Main PYQs