What are the valence electrons? For s-block and p-block elements show that number of valence electrons is equal to its group number.

Monjur Alahi

What are the valence electrons? For s-block and p-block elements show that number of valence electrons is equal to its group number.


0 like 0 dislike
1 views
Share with your friends

1 Answers

Salim Ahmed Kawsar

Call

  • Electrons present in the outermost shell of the atom of an element are called valence electrons.
  • 3Li is an s-block element and its electronic configuration is 1s22s1. Since it has one valence electron, it is placed in group 1.
  • Therefore, for s-block elements, group number = number of valence electrons.
  • However, for p-block elements, group number = 18 – number of electrons required to attain complete octet.
  • 7N is a p-block element and its electronic configuration is 1s22s22p3. Since it has five electrons in its valence shell, it is short of three electrons to complete its octet.
  • Therefore, its group number = 18 – 3 = 15. 

0 like 0 dislike
1 views
Talk Doctor Online in Bissoy App
Successive ionization enthalpies (in eV/atom) of on element are 5,8,9,90,100. The number of valence electrons are:

Number of valence electron =3 as difference between `IE_(3) & IE_(4)` is very high.

2 Answers 1 views
Show that drift velocity of electrons in a conductor is given by u = `J/(ne)` where J is the current density, n is the number of mobile electrons per

Correct Answer - `6.5 xx 10^(-5)ms^(-1)`

2 Answers 1 views
(i) An ………………… is a group or category to which people feel they do not belong.  (in-group / out-group / voluntary group)

(i) out-group (ii) Voluntary group (iii) secondary (iv) reference group (v) Customary (vi) Mores

2 Answers 1 views
In which group should hydrogen be placed? In group 1 or group 17? Why?

Hydrogen contains one valence electron in its valence shell and thus, its valency is one. Therefore, hydrogen resembles alkali metals (group 1 elements) as they also contain one electron in...

2 Answers 1 views
In the long form of the periodic table, ________ group elements can release maximum amount of energy by the addition of electron into is valence shell

Correct Answer - VII

2 Answers 2 views
valence of group IA — i) 4  , valence of group IVA — ii) 0 

D) a → iii, b → i, c → iv, d → ii

2 Answers 1 views
How many s – block and p block elements are there in the third period of the periodic table ? 

Correct option is  D) 2, 6

2 Answers 1 views
The elements a, b, c, d have the following electron configurations. Then the elements that belong to the same group of periodic table is

Correct option is  A) a, b

2 Answers 1 views
Group — Valency  I group — i) +2  ,II group — ii) -1 

B) a → iii, b → i, c → iv, d → ii

2 Answers 1 views
If an element X belongs to II group and another element Y belongs to VII group then the compound formed between these elements has fomula : 

 Correct option is  C) X Y2

2 Answers 1 views
X