Determine the valency of metal and valence electrons with examples?

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Valency of a metal is the number of electrons it usually loses to form a stable ion, and valence electrons are the electrons in its outermost shell. Metals tend to lose outer electrons to reach a noble gas configuration. The number lost is the valency. The electrons available to lose in the outermost shell are the valence electrons. For main-group metals, valency often equals the count of valence electrons; for some transition metals, multiple valencies are possible.

How to find valency

Look at the group number (for groups 1, 2, and 13):
Group 1 → valency 1; Group 2 → valency 2; Group 13 → usually valency 3.
Metals lose electrons → form cations (e.g., Na⁺, Mg²⁺, Al³⁺).
Transition metals may show variable valency (Fe²⁺/Fe³⁺, Cu⁺/Cu²⁺).

Valence electrons vs. Valency

Element	Electronic configuration (outer)	Valence electrons	Common valency	Ion formed
Sodium (Na)	…3s¹	1	1	Na⁺
Magnesium (Mg)	…3s²	2	2	Mg²⁺
Aluminium (Al)	…3s²3p¹	3	3	Al³⁺
Calcium (Ca)	…4s²	2	2	Ca²⁺
Iron (Fe)	…3d⁶4s²	Generally 2 (4s) with 3d involved	2 or 3 (variable)	Fe²⁺, Fe³⁺
Copper (Cu)	…3d¹⁰4s¹	1 (often)	1 or 2	Cu⁺, Cu²⁺

Steps to determine quickly

Write or recall the element’s group and outer electrons.
If it is a metal, count how many electrons it tends to lose to reach the nearest noble gas.
That number is the valency. Those outer electrons are the valence electrons.

Watch 3-min video & get full concept clarity