Question

What element has three electrons in its 5d sublevel? nd nb ta u

Answer 1

C.) Tantalum has three electrons in 5d-sublevel.

Answer 2

Ta: tantalum

Step-by-step explanation:

I list the elements, its atomic number and electronic configuration:

Nd – 60

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(10)4p^(6)5s^(2)4d^(10)5p^(6)6s^(2)4f^(4)`

Nb – 41

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(10)4p^(6)5s^(2)4d^(3)`

Ta – 73

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(10)4p^(6)5s^(2)4d^(10)5p^(6)6s^(2)4f^(14)5d^(3)`

U – 92

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(10)4p^(6)5s^(2)4d^(10)5p^(6)6s^(2)4f^(14)5d^(10)6p^(6)7s^(2)5f^(4)`

Then, Ta has 3 electrons in its 5d sublevel.

Use the attached image to find the electronic configuration and note that the sum of the superscripts must be equal to the atomic number