define valency in atoms
Answers
Answer:
The combining capacity of an atom is it's valency.
Answer:
Explanation:
Valency is simply the combining power of an elements….the valency determine the chemical formula of a compound…when compound react to form new compound(s) they tend to change their valencies…
In summary….
List of groups with their corresponding valencies
Group 1 elements has a valency of 1
Group 2 elements has a valency of 2
Group 3 elements has a valency of 3
Group 4 elements has a valency of 4
Group 5 elements has a valency of 3
Group 6 elements has a valency of 2
Group 7 element has a valency of 1
Group 8 elements has a valency of 0
Let's see how this determine the chemical formulae
Why water is H2O and not HO2 or 2HO
sometimes we don't know how the formulae of a compound are gotten, we just tend to memories them.
H + O2 ------> ?
Hydrogen is a group element, it means it has a valency of 1
Oxygen is a group 6 element, it means it has a valency of 2…
When compounds react, they exchange their valencies..Which means that the valency of Oxygen will move to hydrogen and the valency of hydrogen will move to oxygen to form H20
H + O2-----> 2H20
EXAMPLE 2
when calcium react with chlorine what is the formula of the compound?
Solution
Calcium is a group 2 element with valency of 2 while chlorine a group 7 element with valency of 1…..
When compounds react to form a new compound they exchange their valencies..therefore we will have CaCl2
Hope you understand…..
Valency and oxidation number are the same the only difference is the signs
Groups and corresponding oxidation no.
Group 1 oxidation no. of +1
Group 2 oxidation no. Of +2
Group 3 oxidation no. Of +3
Group 4 oxidation no. Of +4 or -4
Group 5 oxidation no. Of -3
Group 6 oxidation no. Of -2
Group 7 oxidation no of -1
Group 8 oxidation no. Of 0
Thanks