(i) Following is

(i)

The type of magnetism shown by the above diagram is Ferrimagnetism. Ferrimagnetism arises due to the unequal number of domains in opposite direction resulting in the some net magnetic moment.

When these substances are heated, they lose the property of ferrimagnetism and become paramagnetic.

(ii) For octahedral void:

r = 0.414 R

(iii) For body-centered cubic unit cell:

r =

As edge length (a) = 316.5 pm

∴ r =

⇒ r = 136.88 pm

Thus, the radius of tungsten atom is 136.88 pm