CHY 102 Chapter Notes - Chapter 2: Actinium, Scanning Tunneling Microscope, Nonmetal
14 Sep 2020
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Document Summary
Scanning tunneling microscopy = a technique that can image, and even move, individual atoms and molecules. This process is sensitive to the distance between the tip and the surface. If it does over an atom, it recalibrates and moves upwards to keep the current constant. Therefore, this helps locate specific atoms on the material. If the current weakens, the tip is moved closer to the surface. Later, they learned how to pick up and move atoms and molecules. Atom = smallest identifiable unit of element. 2. 2 - early ideas about the building blocks of matter: Democritus = matter was ultimately composed of small, indivisible particles called atomos. Aristotle = different substances were composed of various proportions of fire, air, earth and water. 2. 3 - modern atomic theory and the laws that led to it: In a chemical reaction, matter is neither created nor destroyed. During a chemical reaction, total mass of substances does not change.
