Question

Samarium, Sm, is a member of the lanthanide series. Identify the element just below samarium in the periodic table. By how many units of the atomic numbers of these two elements differ?

Answer 1

Europium (Eu) lies just below samarium (Sm) in the periodic table and their atomic numbers differ by one unit.

Step-by-step explanation:

The element located just below samarium (Sm, atomic number 62) in the periodic table is europium (Eu, atomic number 63). The lanthanide series, to which samarium belongs, is characterized by elements in the first row or the f-block, with atomic numbers ranging from 57 to 71. The atomic numbers of samarium and europium differ by one unit.

When samarium forms a trication by losing three electrons, these electrons are removed from the 6s and 4f orbitals, resulting in the Sm³⁺ configuration of 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶4fµ.