Test1-soln - Name_ Team#_ 1 ENGR 213 Test #1a 25 SEP 02...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Name_______________________________ Team#_________ 1 ENGR 213 Test #1a 25 SEP 02 Attempt all problems. SOLUTION 1. Define bonding energy and give characteristic ranges for the three types of primary bond. The energy required to separate (to infinity) two bonded atoms. 4 points Ionic: 600 – 1500 kJ/mol or 3 -- 8 eV/atom 2 pts each answer Covalent: 70 – 700 kJ/mol or 0.7 – 7 eV/atom Metallic: 70 – 850 kJ/mol or 0.7 – 9 eV/atom 2. Describe how bonding energy affects the melting point of a material. Larger bonding energies require higher temperatures 8 pts Because bonds must be broken for melting to occur 2 pts 3. Calculate the APF for a BCC crystal structure. APF = (volume of ions or atoms in unit cell) / (volume of unit cell) 4 pts For BCC crystal, there are two atoms per cell 1 pts Volume of ions in cell = 2(4 π R 3 /3) = 8 π R 3 /3 1 pt Volume of cell = (4R/ 3) 3 1 pt APF = (3 3)(8 π R 3 )/(3x64R 3 ) = 3 π /8 = 0.68 3 pt 4. Calculate the theoretical density of fluorite CaF
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This test prep was uploaded on 03/26/2008 for the course ENGR 213 taught by Professor Dr.stubbs during the Fall '04 term at Texas A&M.

Page1 / 2

Test1-soln - Name_ Team#_ 1 ENGR 213 Test #1a 25 SEP 02...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online