Question

Element with atomic number 57 belongs to which block

Answer 1

Electronic Configuration of the atom having atomic number 57 by the Aufbau's Principle is,

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 5d¹ 6s²

Now, The Period of the Element is 6th.

Block of the element will corresponds to that shell which receives the last electrons.

Since, the last electrons is received by the 5d subsheell, therefore, the block the given element is the d.

Now, since, it is d-block element, therefore, group = 2 + electrons is (n-1)d subshell = 2 + 1 = 3.

It is Lanthanum.

Hope it helps .

Answer 2

Answer:

Fact box

Group Lanthanides 920°C, 1688°F, 1193 K

Period 6 3464°C, 6267°F, 3737 K

Block d 6.15

Atomic number 57 138.905

State at 20°C Solid 139La