Which combination of atoms can form a polar covalent bond ?
H and N
H and Br
N and N
Na and Br
B.
H and Br
When there is less difference in electronegative of two atoms ( electronegativities are not same) difference in theirsize, polar covalent bond form.
(a) H and H:No difference in electronegativites, so form non-polar covalent bond.
(b) H and Br:Small difference in electronegativities and large difference in size. Hence, form polar covalent bond.
(c) N and N : Same electronegativity, so non-polar covalent bond.
(d) Na and Br:Large difference in electronegativities, hence electrovalent bond is formed.
Consider the following ions:
(i) Ni2+ (ii) Co2+ (iii) Cr2+ (iv) Fe3+
(Given, at. no. Cr = 24, Fe = 26, Co = 27, Ni = 28)
The correct order of magnetic moment of these ions is
(i) < (ii) < (iii) < (iv)
(iv) < (ii) < (iii) < (i)
(i) < (iii) < (ii) < (iv)
(iii) < (iv) < (ii) < (i)
The electron configuration of the oxide ion is much most similar to the electron configuration of the
sulphide ion
nitride ion
oxygen atom
nitrogen atom