A hanging tungsten wire with diameter 0.8 mm (0.8 × 10-3 m) is initially 0.85 m long. When a 106 kg mass is hung from it, the wire stretches an amount 4.88 mm. A mole of tungsten has a mass of 184 grams, and its density is 19.3 g/cm3. Find the approximate value of the effective spring stiffness of the interatomic bond.