{"id":7306,"date":"2021-06-08T21:55:36","date_gmt":"2021-06-08T21:55:36","guid":{"rendered":"https:\/\/opentextbc.ca\/introductorychemistry\/part\/chapter-3-atoms-molecules-and-ions\/"},"modified":"2021-09-21T23:09:21","modified_gmt":"2021-09-21T23:09:21","slug":"chapter-3-atoms-molecules-and-ions","status":"publish","type":"part","link":"https:\/\/opentextbc.ca\/introductorychemistry\/part\/chapter-3-atoms-molecules-and-ions\/","title":{"raw":"Chapter 3. Atoms, Molecules, and Ions","rendered":"Chapter 3. Atoms, Molecules, and Ions"},"content":{"raw":"Although not an SI unit, the angstrom (\u00c5) is a useful unit of length. It is one ten-billionth of a metre, or 10\u221210<\/sup> m. Why is it a useful unit? The ultimate particles that compose all matter are about 10\u221210<\/sup> m in size, or about 1 \u00c5. This makes the angstrom a natural\u2014though not approved\u2014unit for describing these particles.\r\n\r\nThe angstrom unit is named after Anders Jonas \u00c5ngstr\u00f6m, a nineteenth-century Swedish physicist. \u00c5ngstr\u00f6m\u2019s research dealt with light being emitted by glowing objects, including the sun. \u00c5ngstr\u00f6m studied the brightness of the different colors of light that the sun emitted and was able to deduce that the sun is composed of the same kinds of matter that are present on the earth. By extension, we now know that all matter throughout the universe is similar to the matter that exists on our own planet.\r\n\r\n[caption id=\"attachment_7305\" align=\"aligncenter\" width=\"300\"]\"\" Figure 3.0 \"The Sun.\" Anders Jonas \u00c5ngstrom, a Swedish physicist, studied the light coming from the sun. His contributions to science were sufficient to have a tiny unit of length named after him, the angstrom, which is one ten-billionth of a metre.[\/caption]\r\n\r\nThe basic building block of all matter is the atom. Curiously, the idea of atoms was first proposed in the fifth century BCE, when the Greek philosophers Leucippus and Democritus proposed their existence in a surprisingly modern fashion. However, their ideas never took hold among their contemporaries, and it wasn\u2019t until the early 1800s that evidence amassed to make scientists reconsider the idea. Today, the concept of the atom is central to the study of matter.\r\n

Media Attributions<\/h3>\r\nFigure 3.0\r\n