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

Answer:

Ta: tantalum

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