The density of copper is `8.9 times 10^3\ kg//m^3`. and each copper atom has a mass of `63\ u`. Estimate the average distance between neighboring copper atoms. Given: `ρ_c = 8.9 times 10^3\ kg//m^3` `am_c = 63\ u` Known: `1\ u = 1.66 times 10^(-27)\ kg` Solution: `am_c = 63 times 1.66 times 10^(-27) = 1.05 times 10^(-25)\ kg` atoms per cubic meter `= (8.9 times 10^3 kg//m^3)/(1.05 times 10^(-25)) = 8.5 times 10^28 a t oms//m^3` atoms per meter `= ( 8.5 times 10^28 a t oms//m^3)^(1/3) = 4.4 times 10^9 a t oms//m` `d = 1/(4.4 times 10^9 a t oms//m) = 2.3 times 10^(-10)\ m`