What is Matter? Matter describes everything here in our world. Things that we touch, see, smell or feel. In other words, Matter is anything that has mass and takes up space. What is Atom? Atom is the smallest unit of matter. The word is derived from a Greek word that means "cannot be divided". Atoms are made of smaller particles; Protons, Neutrons and Electrons. What is a Proton, Neutron and an Electron? A proton is the positively charged particles in an atom. A neutron is a particle with no charge and An electron is the negatively charged particles in an atom. Protons and Neutron can be found in the nucleus or the center part of an atom. Meanwhile, the electrons orbits around the nucleus.