Question
Explain the trends in physical properties of group 15 elements.
i. Atomic and ionic radii
ii. Ionization enthalpy
iii. Electronegativity
i. Atomic and ionic radii
ii. Ionization enthalpy
iii. Electronegativity
✓
Answer
i. Atomic and ionic radii:
- Atomic size increases down the group with increasing atomic number.
- The effective nuclear charge in case of group 15 elements is larger than that of group 14 elements. Due to the increased effective nuclear charge, electrons are strongly attracted by the nucleus. Thus, the atomic and ionic radii of group 15 elements are smaller than the atomic and ionic radii of the corresponding group 14 elements.
- On moving down the group, number of shells increases which leads to increased shielding effect and as a result atomic radii and ionic radii increases.
- Due to extra stability of half-filled p-orbitals and relatively smaller size of group 15 elements, ionization enthalpy of group 15 elements is much greater than that of the group 14 elements in the corresponding periods.
- On moving down the group, increase in atomic size and screening effect overcome the effective nuclear charge and thus, ionization enthalpy decreases.
- Due to smaller size and greater effective nuclear charge of atoms, group 15 elements have higher electronegativity values than group 14 elements.
- On moving down the group, electronegativity values decreases due to increase in the size of the atoms and shielding effect.
- Nitrogen is the most electronegative element among group 15 elements. However, there is not much of a difference between the electronegativity values of other elements of group 15.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
$CO_2$ can be represented by following three structures:
Calculate the formal charge on each atom in all the three structures of $CO_2$ molecule. Identify the structure with lowest energy.
→Calculate the formal charge on each atom in all the three structures of $CO_2$ molecule. Identify the structure with lowest energy.
Write a note on homologous series.
Explain the construction of simple distillation unit using neat labelled diagram.
A compound contains $4.07\%$ hydrogen, $24.27\%$ carbon and $71.65\%$ chlorine by mass. Its molar mass is $98.96 g \ mol^{-1}.$ What is its empirical formula and molecular formula? Atomic masses of hydrogen, carbon and chlorine are $1.008,12.000$ and $35.453 u, $respectively
→Explain the formation of an ethene molecule on the basis of hybridization.
Explain the term: Radiocarbon dating in detail.
Explain the formation of water $(H_2O)$ molecule on the basis of hybridization.
→Give IUPAC rules for naming substituted benzene.
A piece of zinc weighing $0.635 g$ when treated with excess of dilute $H_2SO_4$ liberated $200 \ cm^3$ hydrogen at $\text{STP.}$ Calculate the percentage purity of the zinc sample.
→Explain the variation in the following properties of the group 14 elements,
i. Atomic radii
ii. Ionization enthalpy
iii. Electronegativity
i. Atomic radii
ii. Ionization enthalpy
iii. Electronegativity