Question

Binary solid has rocksalt structure. Edge length 400pm radius of cation 75pm

Answer 1

Solution :

a=2(r++r−)

500=2(80+r−)

500=160+r−

500−160=2r−

340=2r−

3402=r−

r−=170

∴ the radius of anion =170pm

Thats the right answer

Answer 2

Answer:

125 pm

Step-by-step explanation:

for NaCl structure,

distance between two nearest ions is : 2 × radius of cation + 2 × radius of anion = a