Answer: Materials that are appropriate for separation using sieving are those that differ in particle size or shape. Sieving is a method of separating particles based on their size and shape by passing them through a sieve or mesh with specific openings. The properties of materials that make them suitable for sieving include particle size distribution, particle shape, homogeneity, and bulk density. Materials with a wide range of particle sizes, consistent shapes, and similar bulk densities are ideal for sieving as they can be separated accurately and efficiently. Sieving is a simple and effective technique commonly used in industries such as food processing, pharmaceuticals, and construction for separating materials based on their physical properties.