16. Which electron notation is incorrect? A. 1s²2s²2p⁶3s²3p¹
B. 1s²2s²2p⁶3s⁶4s²3d¹⁰4p⁶5s¹
C. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d⁷5p⁶6s¹
D. 1s²2s²2p⁶3s²3p⁶​