How are the electrons structures of hydrogen and lithium similar?

The electron structures of hydrogen and lithium are similar in that both elements have their outermost electrons in the first energy level. Hydrogen has one electron in its 1s orbital, while lithium has three electrons, with two in the 1s orbital and one in the 2s orbital. This similarity in the arrangement of electrons reflects their position in the Periodic Table, where both are in the first two groups, indicating a comparable basic electron configuration pattern. However, lithium has an additional energy level, which affects its chemical properties.