4. Materials that are acid neutral and chemically stable over time, preventing rapid decay...

Excavation
Resoration
Conservation
Archival Materials

The answer is Conservation. Conservation involves preventing deterioration and damage to objects or materials of historical, cultural, or scientific significance. Chemical stability and acid neutrality are essential in preserving these objects and materials from decay over time. Conservation efforts involve a range of techniques and treatments, including preventive measures, cleaning, restoration, and the use of appropriate archival materials.