1. The problem statement, all variables and given/known data If elements with principal quantum number n > 4 were not allowed in nature, the number of possible elements would be (A) 60 (B) 32 (C) 4 (D) 64 2. Relevant equations 3. The attempt at a solution I got 36 from the periodic table (2+8+8+18) However, that isn't even an option. The answer is 60. Please help.