Matter is composed of very small particles called atoms, hence matter is not continuous but particulate in nature. However, there is another nature associated with matter, which is wave like nature. You will study about this in more detail in grade 11, where an entire chapter has been devoted to this. Sub-atomic particles like electrons very well exhibit wave nature along with particle nature. However this wave nature is not shown by macroscopic objects which are easily observable. The wavelength that is associated with these objects is too small and not appreciable.