Brain Makeover #4: Atoms (by the 76ers Cheerleaders)

All Matter is Made of Atoms

Professor James Trefil (author of Science Matters, Why Science?, and 30 other books on science literacy) identified 18 key science concepts every adult should know to be a science literate. We’re here to reintroduce adults to science, in a fun way! It’s all part of our Brain Makeover project to increase adult science literacy. Here’s concept #4, presented by 76ers Cheerleader Lauren and explained by Professor James Trefil.  We’ll post one each week (more or less) and it to the Brain Makeover collection.

#4. All matter is made of atoms.

As the science of chemistry developed in the eighteenth century, it became clear that there are two kinds of  materials in the world: there are materials that can be broken down by chemical means (think of wood burning) and those that cannot. The latter class of materials are called ‘elements’. In the early nineteenth century, it was proposed that to each of these elements, there is a small structure called an atom (the term was borrowed from classical Greek philosophy), and that all the other materials are made by combining atoms.

In the early twentieth century, experiments showed that the atom has a definite structure. In the center is a small, massive, positively charged nucleus, which the electrons circle in orbits. The development of the science of quantum mechanics further showed that electrons can change orbits in the atom, absorbing light when they move away from the nucleus, emitting it when they move in the opposite direction.