LITHIUM

Lightest metallic element (7)

Solution has appeared in 2 crosswords (1 across and 1 down):

• Quick crossword No 16,016 — 2021-09-05 23:00:04
  7A: Alkali metal, Li (7)
• Quick crossword No 15,298 — 2019-05-19 23:00:17
  15D: Lightest metallic element (7)