Reading a Triple Beam Balance
By Jill Crowder
Students identify the parts of a triple beam balance and practice measuring the mass of objects.
Measuring Volume Using a Graduated Cylinder
Learners view an explanation of how to read a graduated cylinder by measuring the lowest portion of the meniscus. A quiz completes the activity.
Biomolecules: The Carbohydrates (Video)
By Becky Polk-Pohlman
Viewers watch an introduction to monosaccharides, disaccharides, and polysaccharides. The processes for dehydration synthesis and hydrolysis.
Intermolecular Forces
By Debbie McClinton, Dr. Miriam Douglass, Dr. Martin McClinton
In this well-illustrated activity, learners examine the three types of intermolecular forces: dipole-dipole forces, London or Van der Waals forces, and the hydrogen bond. Two interactive questions are included.
Lewis Dot Structures of Covalent Compounds
By Dr. Miriam Douglass, Dr. Martin McClinton
In this interactive and animated object, students distribute the valence electrons in simple covalent molecules with one central atom. Six rules are followed to show the bonding and nonbonding electrons in Lewis dot structures. The process is well illustrated with eight worked examples and two interactive practice problems.
Peptide Bond Formation
By Richard Wilkosz
In this animated object, learners examine the formation of peptide bonds through dehydration synthesis.
Atomic Symbols, Atomic Numbers, and Mass Numbers
Learners read definitions of atomic symbols, atomic numbers, and mass numbers and then answer questions about the number of neutrons, protons, and electrons in select elements.
The Formation of Ester Bonds in the Synthesis of Lipids
In this animated object, learners examine the formation of ester bonds in the synthesis of lipids using triglyceride biosynthesis as an example. Ester bond formation is described as a dehydration synthesis reaction.
Precipitation Reactions
In this interactive and animated object, learners use solubility rules to predict when an insoluble ionic compound will precipitate in a double replacement reaction. Step-by-step examples are given.
Oxidation Numbers
Learners assign oxidation numbers to atoms in neutral compounds and in polyatomic ions. Six examples are worked through in detail, and three problems are provided.
Balancing Oxidation-Reduction Equations
In this animated activity, learners examine the terms "half-reaction," "oxidizing agent," and "reducing agent" and follow five interactive examples to balance equations for oxidation-reduction reactions. Three problems are provided as a self-check.
Unit Conversions
By Jill Larson
In this animated and interactive object, learners follow two rules to write unit conversion fractions.
The Effect of Temperature on the Vapor Pressure of a Liquid
Learners examine how vapor pressure is calculated. The vapor pressure of a liquid increases with increasing temperature. If the heat of vaporization and the vapor pressure at one temperature are known, the vapor pressure at a second temperature can be calculated.
Energy in Chemical Reactions
By Dr. Miriam Douglass
In this animated and interactive object, learners examine kinetic and potential energy as well as the first law of thermodynamics and the flow of energy between a system and its surroundings. Students also answer questions about exothermic and endothermic reactions
How Pressure Changes Boiling Temperature
By Terry Bartelt, Terry Fleischman
Learners study the effect that pressure has on boiling temperatures. Once a liquid has reached a full boil, additional heat does not raise the liquid’s temperature; however, pressure can vary the boiling point of a liquid. A brief quiz completes the activity.
Atomic Structure and Ionic Bonding
In this animated object, learners examine the chemistry behind table salt.
Oxidation-Reduction Reactions
Learners examine the meaning of oxidation, reduction, and half-reaction, and watch a film showing the deposition of copper metal from the reduction of copper (II) ion by aluminum. A brief quiz completes the activity.
Ions
Ions are electrically charged particles obtained from an atom or from a chemically bonded group of atoms by adding or removing electrons. Eight examples illustrate the number of protons, neutrons, and electrons in positive ions (cations) and in negative ions (anions).
Phase Diagrams
Learners examine phase diagrams that show the phases of solid, liquid, and gas as well as the triple point and critical point.
Heat of Fusion and Heat of Vaporization
Learners examine graphs and read that the heat of fusion is the heat energy absorbed by one mole of solid as it is converted to liquid, while the heat of vaporization is the heat energy absorbed by one mole of liquid as it is converted to gas.
Covalent Bonds
In this animated object, students examine what happens when electrons share molecules.
Gas Volume vs. Temperature (Charles's Law)
In this animated object, learners examine how gas volume varies directly with absolute temperature (K at constant pressure). An example of a sample of gas at two conditions of volume and temperature is used to illustrate the law.
Phase Transitions
Learners examine how melting, vaporization, and sublimation require energy input while freezing and condensation release energy.
Learning the Elements of the Periodic Table by Name or Symbol
By Mona Wenrich
Students practice identifying common elements from the periodic table by name or symbol.
The Mole and Avogadro's Number
Learners examine how chemists use moles to "count" atoms by weight. Examples are given.