Atoms

Why are atoms considered the basic building blocks of matter even though smaller particles such as protons and electrons exist?
Everything around us is made up of atoms. The chair you sit on is made up of atoms, the pages of a book, the air you breathe, the grass, rocks, and trees out doors are all made up of atoms. An atom is incredibly tiny--more than a million times smaller than the thickness of a human hair. The smallest speck that can be seen under an ordinary microscope contains more than 10 billion atoms. The diameter of an atom ranges from about 0.1 to 0.5 nanometer. A nanometer is…