Answer:
10
Step-by-step explanation:
Xenon has 54 electrons so it's electron configuration is:
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶
so 4d has 10 electrons
5.9m questions
7.8m answers