An atom is the smallest particle of an element that Can take part in a chemical reaction. Example are an oxygen atom, a hydrogen atom, a nitrogen atom and a sodium atom.

An element is a pure substance which cannot be split into two or more simpler substances by chemical means. Examples of elements are copper, gold, magnesium, carbon and sulfur

Atoms all of the same kind make up an element. Individual atoms of an element are invisible, while sample of an element is easily seen. An element can be solid, for example copper, iron or Carbon or liquid for example mercury or bromine or gas for example oxygen or hydrogen.

References

1.      Manahan, Stanley E. "FRONTMATTER" Environmental Chemistry, Boca Raton: CRC Press LLC, 2000

2.      FHSST Authors, The Free High School Science Texts: Textbooks for High School Students Studying the Sciences Chemistry Grades 10 – 12, Version 0, November 9, 2008