Question

list all the exceptions of electronic configuration all the elements wid exceptions in chemistry wid the reason behind that

Answer 1

There is a general reason for the exception is for stability only the electronic configuration are slightly changed.

Period 4:
Chromium-24 [Ar] 3d⁵4s¹
Copper-29 [Ar] 3d¹⁰4s¹
Period 5:
Niobium - 41 [Kr] 5s¹ 4d⁴
Molybdenum-42 [Kr] 5s¹ 4d⁵
Ruthenium-44 [Kr] 5s¹ 4d⁷
Rhodium- 45 [Kr] 5s¹ 4d⁸
Palladium-46 [Kr] 4d¹⁰
Silver-47 [Kr] 5s¹ 4d¹⁰
Period 6:
Lanthanum-57 [Xe] 6s² 5d¹
Cerium-58 [Xe] 6s² 4f¹ 5d¹
Gadolinium-64 [Xe] 6s² 4f⁷ 5d¹
Platinum-78 [Xe] 6s¹ 4f¹⁴ 5d⁹
Gold-79 [Xe] 6s¹ 4f¹⁴ 5d¹⁰
Period 7:
Actinium-89 [Rn] 7s² 6d¹
Thorium-90 [Rn] 7s² 6d²
Protactium-91 [Rn] 7s² 5f² 6d¹
Uranium-92 [Rn] 7s² 5f³ 6d¹
Neptunium-93 [Rn] 7s² 5f⁴ 6d¹
Curium-96 [Rn] 7s² 5f⁷ 6d¹
Lawrencium-103 [Rn] 7s² 5f¹⁴ 7p¹