Question

PLZ ANSWER FAST , I'LL MARK AS BRAINIST
the third period contains only 8 elements even though the electron capacity of third shell is 18
GIVE LONG AND EASY ANSWER ...NOT FROM GOOGLE PLZ
20PTS​

Answer 1

IT IS BECAUSE ALL THE EIGHT ELEMENTS HAS 3 SHELLS OTHER THAN THAT ALL HAS LESS ALL MORE SHELLS.

YES IT IS CORRECT THAT

3RD SHELL HAS 18 ELECTRONS

BUT THE ELEMENTS LIKE

Calcium Has

electronic configuration

2,8,8,2

in this 3rd shell doesn't contain 10 ELECTRONS as it can hold 18 ,but if it will contain 10 it will not be stable.

so to maintain stability it has only 8 in 3rd shells.

Answer 2

Answer:

Argon (Ar) is the last element of the third period and has a capacity of maximum 18 electrons. Its octet of electrons is completed and as argon belongs to zero group, the third shell contains 18 electrons.

Explanation: