If the atomic number of an element is 11, what will be its correct name, symbol and valency ?

The element with atomic number 11 is Sodium, with the chemical symbol Na (from Latin 'natrium'). Its electronic configuration is 2, 8, 1 — meaning it has one valence electron in its outermost shell, giving it a valency of 1. Sodium readily loses this single valence electron to form Na⁺ ions. Lithium has atomic number 3, Boron has atomic number 5, and Magnesium has atomic number 12.