In a pure substance is a chemical element which contains the base particle and atomic number is the number of protons in the nucleus of the element. Examples of the elements carbon, oxygen, such as the familiar aluminum.
The chemical element is a pure substance consisting of elementary particles, atomic number. As the number of protons in the nucleus. Examples of elements such as carbon, oxygen, aluminum familiar.
The chemical element is a compound which is composed of elementary particles atomic number. The number of protons in the nucleus of the elements. Familiar examples elements such as carbon, oxygen, aluminum.