Question

which type of matter doesn't have constant properties and composition?​

Answer 1

Answer:

It doesn't matter if the atoms are in groups, as in P4 or S8, or isolated, as in Na. As long as there is only one kind of atom, the substance is an element. Elements cannot be chemically broken down into anything smaller and still retain the properties of the element.

Answer 2

Answer:

Pure Substances: Elements and Compounds

Pure Substances: Elements and CompoundsIt doesn't matter if the atoms are in groups, as in P4 or S8, or isolated, as in Na. As long as there is only one kind of atom, the substance is an element. Elements cannot be chemically broken down into anything smaller and still retain the properties of the element.