What do potassium and krypton have in common and what are their differences based on their location on the periodic table?

Common based on their location in Periodic Table;

Potassium has an atomic number 19. Its electronic configuration is as follow;

                                       1s², 2s², 2p⁶, 3s², 3p⁶, 4s¹

And Krypton has an atomic number of 36. Its electronic configuration is as follow;

                                1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶

It is concluded that both Potassium and Krypton has their valence electrons in 4rth shell or they have same Principle Quantum Number.

Difference based on their location in Periodic Table;

As observed in electronic configuration Potassium has one valence electron in its valence shell (i.e. 4s¹) while, Krypton has eight valence electrons in its valence shell (i.e. 4s², 4p⁶). Therefore, they are different in the number of valence electrons.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

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