Socrates Fellows Our Projects Chemistry Electron Density
Electron Density and Solutions and Solubility
Electron Density
Abstract
The students will carry out several different exercises in dropping marbles on to folded paper that has sheets of carbon paper underneath it. This will then be used to show how patterns of electron density have be organized into different shapes based on the number of nodes, or blank spaces, around the nucleus. The exercise will be concluded with some exploratory questioning on orbital shapes on how the patterns may appear in 3-D, using balloons to model the shapes of the orbitals.
Grade Level: 9-12
Duration: 1 (50 minute) period
Learning Objectives:
Students will understand:
• How electron density is localized around an atom in discrete areas, which produces the orbitals where electrons are likely to be found.
• Why a large number of points, or samples, is important for interpreting the data and drawing conclusions.
• How electron orbitals overlap each other, forming layers around the nucleus of an atom and giving rise to distinct energy levels.
Students will be able to:
• Define the shapes of S, P, and D orbitals around the nucleus of an atom.
• Relate the electron orbitals to three-dimensional shapes around the atom
• Show where an electron is most likely, and least likely, to be found at a particular energy level.
Where Did It All Go? - Solutions and Solubility Activity
Abstract
The students will carry out several different exercises in order to gain a better understanding of what makes a solution heterogeneous or homogeneous. This is followed by different examples of solubility of gases, liquids, and solids with regards to changes in temperature and pressure. Finally, students will be given a chance to work with computer simulations on how soluble and slightly soluble materials interact with a solvent on the molecular level.
Grade Level: 9-12
Duration: 2 (50 minute) period
Learning Objectives:
Students will understand:
• The deference between heterogeneous and homogeneous mixtures.
• The interaction of salts and polar solvents like water on a molecular level.
• How temperature and pressure can affect the solubility of a substance.
Students will be able to:
• Define solvent, solute, and solubility.
• Determine if a solution is heterogeneous or a homogeneous mixture.
• Use a computer simulation of a salt dissolving in water to express the difference in solubility constants.
