(i) (a) Following is the schematic alignment of magnetic moments :

What type of magnetism is shown by this substance ?
(b) What type of stoichiometric defect is shown by (i) KCI (ii) AgCl ?
(ii) An element with density `11.2 g cm^(-3)` forms a fcc lattice with length of `4xxd10^(-8)` cm. Calculate the atomic mass of the element. `(N_(A)=6.02xx10^(23) mol^(-1))`.

Explanation

(a)
(b) KCI shows -Schottky defect (stoichiometic)
(b) AgCl shows - Frenkel defect (Stiochiometric)
(ii) `d=11.2g//cm^3`
`f.c.c., z=4`
`a=4xx10^(-8)cm`
`Na=6.02 xx10^(23)mol^(-1)`
`d=(ZM)/(a^3xxN_a)`
`11.2=(4xxM)/((4xx10^(-8))^3xx6.02xx10^23)`
`M=(11.2xxcancel4xx4xx4xx10^(-24)xx6-02xx10^(23))/(cancel4)`
`M=1078.78xx10^(-1)`
`M=107.89 g//mol`