🟡 An atom is extremely small—so small that millions of them can fit across the width of a human hair.
🔵 The diameter of a typical atom is about 0.1 nanometers, which is one ten-millionth of a millimeter. Atoms are made mostly of empty space, with a tiny, dense nucleus at the center surrounded by electrons.
🟢 Despite their size, atoms are the basic building blocks of everything around us.