Recall that the definition of the curie is 1 Ci = 3.70 × 10¹⁰ disintegrations per second and that this value was originally chosen so that the activity of 1.0 g of ²²⁶Ra would be equal to 1 Ci. Given that ²²⁶Ra has a molar mass of 226.025 g/mol and a half-life of 1600 years, calculate Avogadro’s number.