Mass refers to the amount of matter or substance in an object. It tells us how heavy or light an object is. Mass is measured in units like grams (g) or kilograms (kg). For example, a book might have a ...

Insoluble materials are substances that do not dissolve in liquids like water. When added to water, these materials do not mix or form a solution; instead, they remain separate and can often be seen as solid particles. For example, sand, ...

An example of a soluble material is salt. When you add salt to water, it dissolves completely, forming a clear solution. The particles of salt mix evenly with the water, and you can no longer see the individual grains of ...