List of Posts under Chemistry XI Ch 3

Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) O or F (ii) F or Cl

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 ?

How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?

Among the second period elements the actual ionization enthalpies are in the order Li < B < Be < C < O < N < F < Ne. Explain why (i) Be has higher ∆i H than B (ii) O has lower ∆i H than N and F?

What is the significance of the terms — 'isolated gaseous atom' and 'ground state' while defining the ionization enthalpy and electron gain enthalpy?

Explain why cation are smaller and anions larger in radii than their parent atoms?

Consider the following species : N3- , O2-, F- , Na+ , Mg2+ and Al3+ (a) What is common in them? (b) Arrange them in the order of increasing ionic radii.

How do atomic radius vary in a period and in a group? How do you explain the variation?

Write the atomic number of the element present in the third period and seventeenth group of the periodic table.

In terms of period and group where would you locate the element with Z =114?

On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.