if nitrogen has a valency of 3 then why when it is combined with hydrogen the valency of nitrogen is written as 2
Answers
Answer:
Allied solutions
Grade 8
Chemistry
Chapters in Simplified Middle School Chemistry - Class 8
Exercises in Language of Chemistry
Question 2
Q2) Define the term ‘valency’. With reference to water & ammonia as compounds respectively, state the valency of oxygen & nitrogen. Magnesium [[2, 8, 2]] has valency 2+. Give reasons.
Solution
Transcript
Solution:
Valency is the number of particular atoms combined with or displaced with another atom to form a compound.
Water which is H_2
2
O, two atoms of hydrogen combine with one atom of oxygen. The valency of oxygen is 2, because it needs two atoms of hydrogen to form water.
Ammonia which is NH_3
3
, One atom of nitrogen combines with 3 atoms of hydrogen. The valency of nitrogen is 3 because it needs 3 atoms of hydrogen to form ammonia.
Magnesium has valency equal to 2^+
+
because the electronic configuration of Mg is [2,8,2]. The nearest noble gas to magnesium is neon with electronic configuration of [2,8], to achieve this stable electronic configuration Mg can lose 2 valence electrons, hence its valency is 2^+
+
.