Question

how to find block,group and period with an electronic configuration???For ex --cobalt​

Answer 1

Answer:

For s block elements ,group number is equal to the number of valence electrons. b) For p block elements ,group number is equal to 10+number of electrons in the valence shell. c)For d block elements ,group number is equal to the number of electrons in a (n-1) sub shell + the number of electrons in valence shell.

Explanation:

Answer 2

Answer:

Step 1 is to identify the block of the element after you get its electronic configuration, afterwards,

Here is the algorithm:

(i) If the element belongs to s-block , its group number = Number of valence electrons ( or outermost shell electrons ).

(ii) If the element belongs to p- block , group number = no. of valence electrons +10 .i.e., 10 + np electrons + ns electrons.

(iii) If the element belongs to d-block, Group no. = no. of electrons in (n-1) d subshell + no. of electron/s in ns shell.

(iv) If the element belongs to f-block, group no. = 3.

AND FOR COBALT THIS IS THE ANSWER

Cobalt is part of that elusive iron-cobalt-nickel group within the transition metals. The electron configuration for cobalt is [Ar] 3d7, 4s2.

The commonly written electron configuration using the Aufbau principle has the 3d and 4s sublevels reversed along with the erroneous thinking that 4s is somehow lower in energy than 3d. That is incorrect. The 4s sublevel is higher in energy than the 3d with elements with atomic numbers of 21 and above. Therefore, the 4s is written last in the electron configuration.