A real 50p coin is heavier than a toy plastic 50p coin. Materials that are heavier than objects of the same size are more what?

Properties of materials are characteristics of matter. There are certain words used for describing them and you need them in your vocabulary. The properties of different materials make them useful for different purposes.  For example: Although it floats, cork would not be a very good choice of material if you wished to build an ocean-going ship.