Hydrogen (H) was first, followed by helium (He).
Secrets undiscovered is correct, but this chemical formula is not balanced. Double check your question to make sure
Because Electrons have a negative charge
Answer and Explanation:
The resonance contributor in cyclopentadienone (as shown in the attachment below) results into the compound having a positive charge on the carbonyl group, C=O which accounts for a highly reactive anti-aromatic 4π system. And this illustrates the reason for its instability.