Answer to Question #102378 in General Chemistry for Beverlie

Question

1. Iron (Fe) crystallizes as a body-centered unit cell with an edge length of 287 pm. What is the atomic radius of iron in picometers?
2. Gold has a face-centered cubic structure with a unit cell edge length of 407.8 pm. What is the density of each individual gold atom in g/cm3?
3. Sodium (Na, 22.99 g/mol) and potassium (K, 39.10 g/mol) both adopt a bcc structure. The radius of a potassium atom is approximately 1.23 times that of a sodium atom, and potassium’s density is about 0.862 g/cm3. What is the approximate density of sodium?
4. A crystalline form of molybdenum has a density of 10.28 g/cm3. If the radius of copper atoms is 139 pm, is the molybdenum unit cell (a) simple cubic, (b) body-centered cubic, or (c) face-centered cubic?

Answer 1

1) 124.27 pm

2) 13.1 g/cm³

3) 526 pm

4) b