Labels:text | screenshot | font | number OCR: ATOM .............................................. AN ATOM IS the building block of an element. It is a combination of particles. The nucleus (core) of an atom contains positively charged protons and uncharged (neutral) neutrons. The nucleus is orbited by negatively charged electrons. The word atom comes from the Greek atomus, meaning "not able to be cut." (It was once thought that atoms were indivisible.)
