Question

The atomic number of potassium is 19. What is the valency?

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

Alkali metals (like Na, K, Li) all have valency 1.

Answer 1

The Correct Option is A

Step 1: Electronic configuration.
Potassium (K) has atomic number 19. Its configuration is:
\[ 2, 8, 8, 1 \] Step 2: Valency concept.
Valency is determined by the number of electrons in the outermost shell. Here, it has 1 electron in outer shell.
Step 3: Conclusion.
So, valency of potassium is 1.