CHEM 26100: Quantum Mechanics

The scenario involves an archaeologist analyzing iron in an old building containing nickel-63, which has a known half-life of 92 years. With only 0.78% of the original nickel-63 remaining, the goal is to estimate the year when this discovery was made. We delve into the calculations and principles of first-order decay reactions.

This video shows how to determine the number of molecules in a given sample by utilizing the concept of moles, Avogadro's number (6.022 x 10²³), and the molar mass of the substance. It provides step-by-step calculations for different substances, converting mass to the number of molecules and highlighting the versatile application of this approach.

This discussion revolves around the classification of chemical bonds as ionic, polar covalent, or covalent based on the electronegativity difference between the atoms involved. The general criteria for this classification are explained: a difference greater than 1.7 indicates an ionic bond, between 0.5 and 1.7 signifies a polar covalent bond, and less than 0.5 designates a covalent bond. It then applies these criteria to four specific examples, including the CC bond in ethane (H?CCH?), the KI bo

In this video, we delve into the concept of percent composition by mass, exemplified through the compound chloroform (CHCl?), which was once employed as an inhalation anesthetic despite its associated toxicity. By calculating the percent composition for each element within the compound, we gain valuable insights into its composition and its potential effects on health and properties.

Explore the endothermic reaction between Ba(OH)2·8H2O and NH4NO3 observing its impact on surroundings like the freezing water. Discover why touching the beaker feels cold and learn about heat transfer in such chemical reactions. This video is an insightful demonstration of heat absorption in chemical reactions.

Discover the intricacies of atomic radius and its trends on the periodic table in this video. Unravel the factors influencing atomic size and explore how elements' positions on the periodic table affect their atomic radii.