How many elements are there in the 6th period of the periodic table? Provide your reasoning. 

• A. 18 elements; 18 electrons are required to fill the 5s, 4d, and 5p orbitals
• B. 32 elements; 32 electrons are required to fill the 6s, 4f, 5d, and 6p orbitals
• C. 18 elements; 18 electrons are required to fill the 6s, 5d, and 6p orbitals
• D. 32 elements; 32 electrons are required to fill the 6s, 5f, 4d, and 6p orbitals

Answer: (B)