We are going to write a blog about some concepts of science. We would include the pure substances, mixtures, states of matter and change of state

Pure Substances:

Atoms: is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. 

Elements: one or more of the same kinds of atoms chemically combined.

Compound: is a pure chemical substances consisting of two or more different chemical elements.

Mixture: is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of alloys,solutions, suspensions , and colloids.