How many of the following statements are correct
(i) Carbocations acts as electrophiles
(ii) Free radicals are paramagnetic
(iii) Carbenes have incomplete octet 
(iv) Allyl carbocation is more stable than propyl carbocation
(v) Carbanions stability : $3^0>2^0>1^0>$  methyl 
(vi) Benzyl carbocation is less stable than allyl carbocation
(vii) Isopropyl free radical is less stable than $3^0$ -butyl free radical
(viii) Dichloro carbene has 2 lone pairs
(ix) Carboanions are formed by Heterolysis of a covalent bond.