21Jan 2014 by Vincent Summers No Comments

Transition from Ice to Water to Vapor

Physics
[caption id="attachment_5490" align="alignright" width="440"] Hydrogen Bonding - CCA SA 3.0 Unported by Magasjukur2[/caption] The transition from ice to water to steam. What happens? A block of ice has a temperature well below freezing and is warmed gradually. It reaches above the boiling point. What transitions occur along the way? What are the processes? Transition: Solid to Liquid At first, the heat supplied simply increases the temperature of the ice. The temperature of the surface is somewhat warmer than the ice inside. It takes time for heat to penetrate. Eventually, the outer layer of the ice reaches the melting point. The outside ice melts first—then the inner ice. [caption id="attachment_5491" align="alignleft" width="220"] Melting Ice[/caption] During melting, the heat energy is spent breaking the stiff hydrogen bonds. None of it is spent…
Read More
20Jan 2014 by Vincent Summers 1 Comment

Organic Chemistry: Pushing Electrons

Chemistry
Scientists desire to solve complex problems with exact precision, but sometimes it just is not practical. Simplifying is necessary. For the organic chemist, one form of simplifying is the idea of pushing electrons. To illustrate, high school physics instructors introduce the concept of massless strings and frictionless pulleys. No such things exist. Still, this fiction enables the beginning student to isolate what is important. Spark Notes informs us that college entrance examinations generally employ such contrivances. Constructs, Artifices, Contrivances Physicists are not the only ones to employ constructs and contrivances to simplify problems and arrive at an answer. The organic chemist must understand very complex compounds and the reactions leading to their formation. One of the best known contrivances is that of pushing electrons or pushing arrows. The great thing…
Read More
17Jan 2014 by Vincent Summers 1 Comment

Examples of Atoms That are Ionized

Chemistry
[caption id="attachment_15556" align="alignleft" width="440"] H +1, H atom, H -1. Image by Jkwchui CC-by-SA3.0[/caption] Not all atoms are atoms that are ionized. All atoms have a nucleus containing protons and neutrons. That nucleus is surrounded by one or more orbitals that contain electrons. The total charge of a neutral atom equals zero. The number of protons equals the number of electrons. If the number of electrons increases or decreases, an atom is ionized. It is either a cation (positive ion) or an anion (negative ion). Atoms That Are Ionized The same thing can happen to small collections of bonded atoms. By definition, an atom oxidizes to a cation or reduces to an anion. Positively Charged Atoms (Cations) Atoms that are ionized have lost energy and become more stable in so…
Read More