What are the difference between sand and potting soil are they both mixtures how do you know?

Sand is a granular material composed of small rock particles, while potting soil is a mixture of organic materials such as peat moss, compost, and perlite. Sand is not a mixture, as it is a single component, while potting soil is a mixture because it contains multiple components blended together. You can tell the difference based on their composition and physical properties.