In sociology and psychology, some definitions include only consciously malignant forms of discrimination. Some definitions of racism also include discriminatory behaviors and beliefs based on cultural, national, ethnic, caste, or religious stereotypes.
A cell is much, much larger than an atom. A typical animal cell might be 10,000 times as wide, long, and tall as a typical atom, or about 1 trillion times the volume of an atom. Another way to arrive at this answer is to consider the fact that cells are made up of atoms, so the atoms must therefore be smaller.
Cells are so small that even a cluster of these cells from a mouse only measures 50 microns. Although it is generally the case that biological cells are too small to be seen at all without a microscope, there are exceptions as well as considerable range in the sizes of various cell types. Eukaryotic cells are typically 10 times the size of prokaryotic cells (these cell types are discussed in the next Chapter).