The discovery of radioactivity proved that atoms could disintegrate.

Evidence

This view prevailed until the discovery of radio-activity, when it was found that atoms could disintegrate. — Bertrand Russell, History of Western Philosophy, 270

Categorization

• corroborated: 2 independent passages support this claim — Bertrand Russell, History of Western Philosophy, 270
• XREF: connects to: Modern physics replaced indestructible matter with persistent energy. — Bertrand Russell, History of Western Philosophy, 271