Find the number of molecules(s) in which direction of back bonding is form surrounding atom to central atom.
`BF_(3),OF_(2),O Cl_(2),ul(N)(CH_(3))_(3),BF_(4)^(-)`

Find the number of molecules (s) in which shape of molecule is changed due to back bonding w.r.t under lined atom. ul(B)Cl_(3),ul(N)(CH_(3))_(3),ul(N)(SiH_(3))_(3),ul(P)(CH_(3))_(3),ul(B)(OCH_(3))_(3)

Find the number of molecule having two lone e^(-) pairs, on central atom. I_(3)^(+), XeF_(2), XeF_(4), H_(2)O, NH_(2)^(-), H_(2)S, SO_(4)^(2-), NF_(3), NO_(2)^(-), XeOF_(2)

Find the number of chemical species, in which 2 p pi -3 d pi back bond is present B(OH)_(3), N(SiH_(3))_(3),P(CH_(3))_(3),N(GeH_(3))_(3),BeCl_(2),O(SiH_(3))_(2),O Cl_(2),BCl_(3)

underline(B)F_(3)+H_(2)O to H_(3)BO_(3)+H[BF_(4)]

underline(B)F_(3)+H_(2)O to H_(3)BO_(3)+H[BF_(4)]

Find the number of molecules which are not having 3e-4c bond from the following Al_(2)(CH_(3))_(6),Si_(2)H_(6),B_(2)H_(6),C_(2)H_(6),Si_(2)Cl_(6),Al_(2)Cl_(6)

total number of molecule which hydrolysed at room temperature and hybridization of central atom is sp^(3)d in transition state: C Cl_(4),SiCl_(4),NCl_(3),PCl_(3),AsCl_(3),SF_(6),P_(4)O_(6),P_(4)O_(10),SeF_(6)

Co-ordination number of central atom in Na_(3)[Al(C_(2)O_(4))_(3)] and [Co(en)_(2)Cl]Cl are:

Find out the total number of compound which have p_(pi)-d_(pi) types of back bonding BF_(3),B_(3)N_(3)H_(6),O(SiH_(3))_(2),(SiH_(3))NCS,Ocl_(2),SCl_(2),PH_(3),PF_(3)

Indicate the sigma & pi bonds in (i) CH_(2)Cl_(2) (ii) CH_(3)-C-=C-CH_(3)