Question

Which of the following arrangements correctly represents hexagonal and cubic close packed structure respectively?

• A. $ABAB.......$ and $ABCABCABC........$
• B. $ABCABC.......$ and $ABAB......$
• C. Both have $ABCABC......$ arrangement
• D. Both have $ABAB.....$ arrangement

Answer 1

The correct option is A $ABAB.......$ and $ABCABCABC........$

$ABAB.......$ and $ACBACB........$ arrangements correctly represents hexagonal and cubic close-packed structure respectively.
Note: $AAAA$ type arrangement represents simple cubic structure.
$ACBACB........$ arrangement can also be represented as $ABCABC........$ arrangement.