Question

all elements in the third period have
1. three complete shells
2. three complete subshells
3. three valence electrons
4. three electrons less than octet​

Answer 1

The principal quantum number of valance electron represents the period of the element. hence,

hence, all elements of third period represent outermost shells of elements .

we know,

according to Bohr's theory

in K - shell = 2 electrons

in L- shell= 8 electrons

in M - shell = 18 electrons.

but in third period maximum number of electrons = 18 ( Ar)

1s² => first shell

2s² , 2p^6 => 2nd shell

3s² , 3P^6, 3d^10=> 3rd shell .

we see last element ( e.g Ar) configuration = 1s², 2s²,2P^6 3s², 3p^6, 3d^0

hence, 3rd shell incomplete , hence option (A) is incorrect .

now , configuration of first element ( e.g Na) = 1s², 2s², 2p^6, 3s¹

we see three subshell ( 1s, 2s , 2p) are complete so, option (B) is correct .

option (C) is incorrect becoz period doesn't depends upon valance electrons .option (D) is also incorrect.

hence, option (B) is correct

Read more on Brainly.in - https://brainly.in/question/1257974#readmore

Answer 2

Answer:

8 to 8.45

Explanation:

English is a good actress and a good person to be a good person to be a part time carer for her birthday present.....

I will send tomorrow

SHOWER SOME LIKES .... MARK MY ANSWER THE BRAINLIEST ONE