Yes. Your body is made up of trillions of cells. Each cell varies in size, but many are 10-100 micrometers in diameter (look at the link I posted below to get a sense of the scale). Your thumb is about 20 millimeters in size, about 1000x larger. Each atom is different, but typically, an atom's diameter is about 0.1 nanometer, which means it's 100,000X smaller than a small cell. All the internal structures of the cell are composed of atoms joined into molecules like the phospholipids and proteins that make up membranes, the DNA in the nucleus, the proteins of the cytoskeleton, plus all the water and other molecules floating around in the cytoplasm. A small molecule like water may have 3 atoms (2 Hydrogens and 1 Oxygen), large molecules like proteins and DNA may have thousands to billions of atoms. Depending on how what cell you're talking about, there's 100's of trillions to quadrillions of atoms in just one human cell.