Historical clue formulations

• Balanced, as some molecules — 2024-03-08
• Electrically neutral, in chemistry — 2023-02-24
• Electrically balanced, in chemistry — 2021-05-22
• Electrically balanced, in chemistry — 2020-10-04
• Lacking + or -, electrically — 2020-09-20
• Like hydra neurons — 2013-02-15
• Lacking radiating appendages, as nerve cells — 1999-09-25