A hexagonal close packed structure and a cubic close packed structure for a given element would be expected to have the same density as
Both have packing efficiency of 74%
Both have coordination number of 12
Both have different packing efficiency and different coordination number
Both (1) and (2) are correct
As we know, Both hexagonal close-packed and cubic close-packed structures have a packing efficiency of 74% and both have the same coordination number of 12.
Therefore, ?Option(4) is correct.