In the ionic ompound `KF`, the `K^(+)` and `F^(-)` ions are found to have partically radii, about `1.34Å` each. What do you predict about the relative covalent radii of K and F?

In the ionic compound KF , the K^(+) and F^(-) ions are found to have practically identical radii, about 1.34 Å each. What can you predict about the relative atomic radii of K & F ?

Which properties of element depend on the electronic configuration of atoms and which do not (b) Why the chemical properties of a group are similar Why do they not have identical properties (c ) Account for the great chemical similarity of the lanthanoid elements (Z =57 to 71) (d) Select the largest species in each group (i) Ti^(2),Ti^(+3) (ii) F^(Θ),Ne,Na^(o+) (e) Select the species with the largest IE in each group (i ) na,K,Rb (ii) F,Ne,Na (f) Which ion has the smallest radius Li^(o+),Na^(o+),K^(o+) Be^(+2), Mg^(+2) (g) Select among the element that has the lowest and highest IE K, Ca, Se, B, Kr , (h) The ionic radii of S^(2-) and Te^(2-) are and 220 pm respectively Predict the ionic radius of Se^(2-) and for p^(3-) (i) In the ionic compound KF the K^(o+) and F^(o+) have practically identical radii, about 134 pm each. Predict the relative atomic radii of 1 K and F .

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If the ionic radii of each K^(+) and F^(-) are 1.34Å , then tha atomic radii of K and F will be respectively:

If the ionic radii of each K^(+) and F^(-) are 1.34Å , then tha atomic radii of K and F will be respectively:

If the ionic radii of K^(+) and F^(-) are nearly the same (i.e., 1.34A^(o) ) ,then the atomic radii of K and F respectively are:

The properties of the elements (atomic/ionic radii, electron gain enthalpy, ionization enthalpy, electronegativity, valence, oxidising/reducing power, acid/base character, etc.) which are directly or indirectly related to their electronic configirations are called periodic properties. These properties show a regular gradation on moving from left to right in a period or form top to bottom in a group. Down a group, the atomic/ionic radii, metallic character and reducing character increase while ionization enthalpy and electronegativity decrease. Along a period from left to right, atomic/ionic and metallic character decrease while ionization enthaloy, electronegativity, non-metallic character and oxiding power increase. However, electron gain enthalpy becomes less negative down a group butmore negative along a period. In contrast, inert gases have positive electron gain enthalpies which do not show may regular trend. If the ionic radii of K^(+) and F^(-) are about 1.34 Å each, then the expected value of atomic radii of K and F should be respectively: