La belongs to group 3 while Hg belongs to group 12 and both belong to period 6
of the periodic table. Write down the general outer electronic configuration of the ten elements from La to Hg together using orbital notation method.
The ten elements starting from La (Lanthanum) to Hg (Mercury) across period 6 are : Lanthanum (La), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Rhenium (Re), Osmium (Os), Iridium (Ir), Platinum (Pt), Aurum (Au), and Mercury (Hg). • Electron configuration of an element is the representation of its number of electrons in the form of s, p, d, and f orbitals. • Also, number of electrons in a neutral atom = Atomic number of the element • The electrons are filled according to the Afbau's principle. • The electronic configuration of the aforementioned elements are as follows : La (57) - [Xe] 5d1 6s2 Hf (72) - [Xe] 4f14 5d2 6s2 Ta (73) - [Xe] 4f14 5d3 6s2 W (74) - [Xe] 4f14 5d4 6s2 Re (75) - [Xe] 4f14 5d5 6s2 Os (76) - [Xe] 4f14 5d6 6s2 Ir (77) - [Xe] 4f14 5d7 6s2 Pt (78) - [Xe] 4f14 5d9 6s1 Au (79) - [Xe] 4f14 5d10 6s1 Hg (80) - [Xe] 4f14 5d10 6s2 [Xe] represents 54 number of electrons as the atomic number of Xe is 54. Therefore, for convenience, 54 electrons are represented as [Xe].