Question

1) What is meant by pure substances ?

Answer 1

substance which doesn't have mixture of two or more substances it is not mixture it is in its pure form

Answer 2

Answer:

A pure substance is one which is made up of only one kind of particles. These particles may be atoms or molecules. For example, sulphur is made up of only one kind of particles (called sulphur atoms), therefore, sulphur is a pure substance. Similarly, water is made up of only one kind of particles (called water molecules), therefore, water is also a pure substance. In fact, all the elements and compounds are pure substances because they contain only one kind of particles. A pure substance is homogeneous throughout its mass. A pure substance cannot be separated into other kinds of matter by any physical process. A pure substance has a fixed composition as well as a fixed melting point and boiling point.