👉 Retentivity is a property of materials that indicates how easily they retain energy or heat. It depends on the material itself, its composition, and the temperature of the surroundings. In general, materials with high retentivity are more likely to retain heat than those with low retentivity, which means they can store more heat in their bulk. On the other hand, materials with low retentivity tend to be less dense or absorb heat more efficiently. The term "retentivity" is