535sir, what is the fundamental mistake in considering r+ =0.732r-?
what will happen if r+r-=0.732(just less than)
then what is the implication of saying if 0.414 ≤r/R ≤0.732, it is an octahedral void?
5 Answers
1357A+ is in the octahedral void of X-.
2r++2r-=2√2r-
r+=(√2-1)r-=0.414*250=103.5≈104 pm
5351357then there is a concept of tightly fit and loosely fit.
when r/R=0.414 it is tightly fit.
as we go on increasing the ratio, it becomes loose
and after 0.732 it is so loose that it changes to BCC
535So sir if not mentioned, we always take it to be tightly fit?
Rajiv Agarwal yes, take it as ideal packing (tightly fit = all are touching each other)Upvote·0· Reply ·2014-03-14 21:58:57- Aditya Agarwal Ok, sir. Thank You. :)
1=> R(+) / R(-) = .414
=> R(+) + R(-) = √2(R-)
=> R(+) = R(-)*(.414)
=> R(+) = 250 * .414
=> R(+) = 104(approx.)
Therefore (A) is the answer