3.1: Properties of Atoms
- Page ID
- 367745
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You learned earlier that all matter in the universe is made out of tiny building blocks called atoms. All modern scientists accept the concept of the atom, but when the concept of the atom was first proposed about 2,500 years ago, ancient philosophers laughed at the idea. It has always been difficult to convince people of the existence of things that are too small to see. But by the early 1800s, there was in fact indirect evidence for the existence of an atom based on experimental results. It wasn’t until the mid-1900s that the technology developed to the point where it was possible to detect atoms directly.
By the early 1900s, all science had accepted the existence of atoms to the point that there was resistance to the idea that there could be something smaller than an atom. In fact, the elements were recognized to be existing as atoms and categorized as the smallest possible form of matter. However, it was about this time that the existence of subatomic particles was detected. There was initial resistance to this idea, however it turned out that these subatomic particles were in fact the explanation for the categories that had already been discovered for the elements!
In this section, we will first discuss atomic theory, then the subatomic particles and their properties.