What is the atomic number of K?

The atomic number of potassium (K) is 19.

Here’s a detailed explanation:

Definition of Atomic Number: The atomic number of an element is the number of protons found in the nucleus of an atom of that element. It is unique for each element and determines the element's identity.

Element Symbol: The symbol for potassium is "K", which is derived from the Latin name "kalium".

Periodic Table Position: Potassium is located in group 1 of the periodic table, specifically in the alkali metals category. It is in period 4.

Electron Configuration: The atomic number also indicates the number of electrons in a neutral atom. For potassium, with an atomic number of 19, the electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹, showing that it has 19 electrons.

In summary, the atomic number of K (potassium) is 19.