Download 28.29. Solve: The density of aluminum is 2700 kg/m3

28.29. Solve: The density of aluminum is 2700 kg/m3, so 1.0 m3 of aluminum has a mass of 2700 kg. The
conduction-electron density is the number of electrons in 1.0 m3. Because the atomic mass of aluminum is 27 u, 27 g
of aluminum contains NA = 6.02 × 1023 atoms. Thus, the number of aluminum atoms in 2700 kg of aluminum is
6.02 × 10 23
(2700 kg) = 6.0 × 10 28
(27 g)
The number density of aluminum atoms is 6.0 × 10 28 m −3 . Since each aluminum atom contributes one conduction
electron to the metal, the number density of conduction electrons in aluminum is n = 6.0 × 10 28 m −3 .
Assess: The number density n obtained above agrees with that given in Table 28.1.