Polonium is the only metal known to exist in a simple cubic lattice form. The density of polonium at 0°C is measured to be $10.00 \mathrm{g} / \mathrm{cm}^{3}$. The atomic radius of polonium would then be (assume the mass of a polonium atom $=2.7 \times 10^{-22} \mathrm{g}$ )
(a)$1.1 \AA$
(b)$1.9 \AA$
(c)$1.5 \AA$
(d)$2.3 \AA$
Answer
Answer: C ✓ checked by 4AB · confidence high
Explanation
Simple cubic, one atom per cell: a³ = m/ρ = 2.7×10⁻²²/10 = 2.7×10⁻²³ cm³ ⇒ a = 3.0 Å; r = a/2 = 1.5 Å.