Sana Sehar 
Astatine (At) joins the party with the halogens. Its outer shell isn’t quite full, holding five electrons in the 6p subshell ([Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵). This incomplete configuration, similar to other halogens like Chlorine (Cl), makes Astatine very reactive. Unlike the noble gases with packed outer shells, Astatine seeks to form bonds to achieve stability.
Radon (Rn) wins the “noble gas club” membership. Its outer shell is full, with a configuration of [Xe] 6s²6p⁶. This complete outer shell, similar to other noble gases like Xenon (Xe), makes Radon very stable and unreactive. There’s no room for chemical shenanigans with a full outer shell!
Francium (Fr) is the lone wolf. It has just one electron in its outermost shell, following the configuration [Rn] 7s¹. This single electron makes it highly unstable, unlike the stable noble gases with full outer shells. This single electron also hints at Francium’s high reactivity.
Radium (Ra) plays it safe with a full outer shell, just like the noble gases. Its electron configuration, written as [Rn] 7s², shows all its outer electrons occupying the 7s subshell. This complete outer shell, similar to its neighbor radon (Rn), contributes to Radium’s stability and low reactivity.
Actinium (Ac) stands out from the others. Unlike its heavier neighbors, Actinium has a mostly filled outer shell, with electrons in the 6d and 7s subshells ([Rn] 6d¹ 7s²). This configuration, closer to noble gases, hints at some stability, but the presence of an electron in the 6d subshell suggests Actinium might be slightly more reactive than a true noble gas
In plutonium (Pu) with 94 electrons, the electron configuration is predicted to be [Rn] 5f⁶ 6d⁰ 7s². This configuration suggests filled inner shells similar to radon (Rn), with six electrons in the 5f subshell, no electrons in the 6d (zero d-electrons), and two in the outermost 7s subshell.
How to write Orbital Diagram of Thallium? Thallium (Tl) possess 81 electrons. Its configuration is ([Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹. Unlike its group members, it has a single electron in the outermost shell (6p¹) alongside a full inner shell (5d¹⁰). This unique setup influences Thallium’s properties, like its melting point and bonding behavior.
Neptunium (Np), with 93 electrons, has the electron configuration [Rn] 5f⁴ 6d¹ 7s². This notation reflects filled inner shells similar to radon (Rn), but with four electrons in the 5f subshell, one in the 6d, and two outermost in the 7s subshell.
Uranium (U) has the electron configuration [Rn] 5f³ 6d¹ 7s². It has filled inner shells like radon (Rn), with three electrons in the 5f subshell, one in the 6d, and two outermost in the 7s subshell.
Protactinium (Pa), with 91 electrons, possesses the electron configuration [Rn] 5f² 6d¹ 7s². It shows filled inner shells as radon (Rn), followed by two electrons in the 5f subshell, one in the 6d, and two outermost in the 7s subshell.
