{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

c123-partb-solutions

c123-partb-solutions - CHEM 123 Practice Problems B1 page 1...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEM 123: Practice Problems page 1 of 30 B1. Simple cubic packing. The crystal lattic and unit cell for simple cubic packing are shown below. a) # spheres = ( ) ( ) 1 8 sphere/corner 8 corners = 1 sphere b) The coordination number of each sphere is 6. To see this, focus on an “interior” sphere such as sphere “A” in the figure on the left. That sphere is in contact with 6 other spheres – the one above it, the one below, the one in front, the one behind, the one to its left and the one to its right. c) If the radius of each sphere is “ R ” then the edge length of the unit cell is a = 2 R d) The volume of the unit cell is V cell = a 3 = 8 R 3 There is one full sphere contained within the unit cell so the volume of spheres contained within the unit cell is 3 spheres 4 3 V R = π . 3 4 3 3 0.5236 6 8 spheres cell V R Packing Efficiency V R π π = = = = A
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon