Question

Identify the group and valency of hte element having atomic number 119. Also predict the outermost electronic configuration and write the general formula of its oxide.

Answer 1

The present set up of the Long form of the periodic table can accommodate a maximum of 118 elements. Thus, in accordance with Aufbau principle, the filling of 8s - orbital will occur. In other words, the 119th electron will enter 8 s-orbital. As such its outmost electronic configuration will be $8s^1$
Since, it has only one electron in the valence shell, i.e. 8s. therefore its valency will be 1 and it will lie in the group IA along with alkali metals and the formula of its oxide iwll be $M_{2}O$ where M represents the element.