If an electron transitions from shell 1 to shell 3, which of the following statements is true regarding the energy required?

• A. The energy required is less than transitioning from shell 2 to shell 3.
• B. The energy required is zero.
• C. The energy required is the same as transitioning from shell 2 to shell 3.
• D. The energy required is greater than transitioning from shell 2 to shell 3.

Answer: (D)