Question

explain the valency of an element with atomic number 27

Answer 1

an element with atomic number 27 is cobalt.
the valency of cobalt is 4
valency of an element is the number of electrons in the outermost shell of the atom

Answer 2

$\huge\textbf{Valency :}$

Valency tells us how many electrons does an atom need to loose, gain and share to attain a stability to form a compound.

$\textbf{Valency of First 20 elements are :}$

1) Hydrogen (H) :- +1

2) Helium (He) :- 0

3) Lithium (Li) :- +1

4) Beryllium (Be) :- +2

5) Boron (B) :- +3

6) Carbon (C) :- ±4

7) Nitrogen (N) :- -3

8) Oxygen (O) :- -2

9) Fluorine (F) :- -1

10) Neon (Ne) :- 0

11) Sodium (Na) :- +1

12) Magnesium (Mg) :- +2

13) Aluminium (Al) :- +3

14) Silicon (Si) :- ±4

15) Phosphorus (P) :- -3,-5

16) Sulphur (S) :- -2

17) Chlorine (Cl) :- -1

18) Argon (Ar) :- 0

19) Potassium (K) :- +1

20) Calcium (Ca) :- +2

$\textbf{The name of element with 27 atomic number is}$

$\textbf{Cobalt and it's Valency is +4 and -4}$

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