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Unit 1: Atomic Structure and Properties
Element Builder
Use protons, neutrons, and electrons to build elements. As the number of protons, neutrons, and electrons changes, information such as the name and symbol of the element, the Z, N, and A numbers, the electron dot diagram, and the group and period from the periodic table are shown. Each element is classified as a metal, metalloid, or nonmetal, and its state at room temperature is also given.
Average Atomic Mass
The atomic mass for each element listed in the periodic table is actually the weighted average mass of all of the different isotopes of the element. In the Average Atomic Mass Gizmo, use a mass spectrometer to separate an element into its isotopes. Then, calculate the average atomic mass by considering the mass and abundance of each isotope.
Moles
Understand the definition of a mole and determine the Avogadro constant by adding atoms or formula units to a balance until the mass in grams is equal to the atomic or formula mass. Manipulate a conceptual model to understand how the number of particles, the number of moles, and the mass are related. Then use dimensional analysis to convert between particles, moles, and mass.
Periodic Trends
Explore trends in atomic radius, ionization energy, and electron affinity in the periodic table. Measure atomic radius with a ruler and model ionization energy and electron affinity by exploring how easy it is to remove electrons and how strongly atoms attract additional electrons. View these properties on the whole periodic table to see how they vary across periods and down groups.
Bohr Model: Introduction
Fire photons to determine the spectrum of a gas. Observe how an absorbed photon changes the orbit of an electron and how a photon is emitted from an excited electron. Calculate the energies of absorbed and emitted photons based on energy level diagrams. The light energy produced by the laser can be modulated, and a lamp can be used to view the entire absorption spectrum at once.
Mystery Powder Analysis
Perform multiple experiments using several common powders such as corn starch, baking powder, baking soda, salt, and gelatin. The results of the research on the known powders can then be used to analyze several unknowns using the scientific method. The unknowns can be a single powder or a combination of the known powders.
Unit 2: Molecular and Ionic Compound Structure and Properties
Ionic Bonds
Simulate ionic bonds between a variety of metals and nonmetals. Select a metal and a nonmetal atom, and transfer electrons from one to the other. Observe the effect of gaining and losing electrons on charge, and rearrange the atoms to represent the molecular structure. Additional metal and nonmetal atoms can be added to the screen, and the resulting chemical formula can be displayed.
Polarity and Intermolecular Forces
Combine various metal and nonmetal atoms to observe how the electronegativity difference determines the polarity of chemical bonds. Place molecules into an electric field to experimentally determine if they are polar or nonpolar. Create different mixtures of polar and nonpolar molecules to explore the intermolecular forces that arise between them.
Unit 3: Intermolecular Forces and Properties
Density Laboratory
With a scale to measure mass, a graduated cylinder to measure volume, and a large beaker of liquid to observe flotation, the relationship between mass, volume, density, and flotation can be investigated. The density of the liquid in the beaker can be adjusted, and a variety of objects can be studied during the investigation.
Density Experiment: Slice and Dice
Drop a chunk of material in a beaker of water and observe whether it sinks or floats. Cut the chunk into smaller pieces of any size, and observe what happens as they are dropped in the beaker. The mass and volume of each chunk can be measured to gain a clear understanding of density and buoyancy.
Archimedes' Principle
Place weights into a boat and see how far the boat sinks into a tank of liquid. The depth of the boat can be measured, as well as the amount of liquid displaced. The dimensions of the boat and the density of the liquid can be adjusted. See how much weight the boat can hold before it sinks to the bottom!
Phase Changes
Explore the relationship between molecular motion, temperature, and phase changes. Compare the molecular structure of solids, liquids, and gases. Graph temperature changes as ice is melted and water is boiled. Find the effect of altitude on phase changes. The starting temperature, ice volume, altitude, and rate of heating or cooling can be adjusted.
Solubility and Temperature
Add varying amounts of a chemical to a beaker of water to create a solution, observe that the chemical dissolves in the water at first, and then measure the concentration of the solution at the saturation point. Either potassium nitrate or sodium chloride can be added to the water, and the temperature of the water can be adjusted.
Boyle's Law and Charles's Law
Investigate the properties of an ideal gas by performing experiments in which the temperature is held constant (Boyle's Law), and others in which the pressure remains fixed (Charles's Law). The pressure is controlled through the placement of masses on the lid of the container, and temperature is controlled with an adjustable heat source. Gay-Lussac's law relating pressure to temperature can also be explored by keeping the volume constant.
Solubility and Temperature
Add varying amounts of a chemical to a beaker of water to create a solution, observe that the chemical dissolves in the water at first, and then measure the concentration of the solution at the saturation point. Either potassium nitrate or sodium chloride can be added to the water, and the temperature of the water can be adjusted.
Temperature and Particle Motion
Observe the movement of particles of an ideal gas at a variety of temperatures. A histogram showing the Maxwell-Boltzmann velocity distribution is shown, and the most probable velocity, mean velocity, and root mean square velocity can be calculated. Molecules of different gases can be compared.
Ideal Gas Law
Explore relationships between amount, temperature, pressure, and volume for an ideal gas in a chamber with a moveable piston. Discover rules of proportionality contained in Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law. Use these relationships to derive the ideal gas law and calculate the value of the ideal gas constant.
Melting Points
Every substance has unique transition points, or temperatures at which one phase (solid, liquid, or gas) transitions to another. Use a realistic melting point apparatus to measure the melting points, boiling points, and/or sublimation points of different substances and observe what these phase changes look like at the microscopic level. Based on the transition points, make inferences about the relative strengths of the forces holding these substances together.
Unit 4: Chemical Reactions
Chemical Changes
Chemical changes result in the formation of new substances. But how can you tell if a chemical change has occurred? Explore this question by observing and measuring a variety of chemical reactions. Along the way you will learn about chemical equations, acids and bases, exothermic and endothermic reactions, and conservation of matter.
Chemical Equations
Practice balancing chemical equations by changing the coefficients of reactants and products. As the equation is manipulated, the amount of each element is shown as individual atoms, histograms, or numerically. Molar masses of reactants and products can also be calculated and balanced to demonstrate conservation of mass.
Unit 5: Kinetics
Half-life
Investigate the decay of a radioactive substance. The half-life and the number of radioactive atoms can be adjusted, and theoretical or random decay can be observed. Data can be interpreted visually using a dynamic graph, a bar chart, and a table. Determine the half-lives of two sample isotopes as well as samples with randomly generated half-lives.
Unit 6: Thermodynamics
Reaction Energy
Exothermic chemical reactions release energy, while endothermic reactions absorb energy. But what causes some reactions to be exothermic, and others to be endothermic? In this simulation, compare the energy absorbed in breaking bonds to the energy released in forming bonds to determine if a reaction will be exothermic or endothermic.
Feel the Heat
Have you ever used a glove warmer to keep your hands warm? How about an instant cold pack to treat an injury? In the Feel the Heat Gizmo, create your own hot and cold packs using various salts dissolved in water and different bag materials. Learn about exothermic and endothermic processes and how energy is absorbed or released when bonds are broken and new bonds form.
Calorimetry Lab
Investigate how calorimetry can be used to find relative specific heat values when different substances are mixed with water. Modify initial mass and temperature values to see effects on the system. One or any combination of the substances can be mixed with water. A dynamic graph (temperature vs. time) shows temperatures of the individual substances after mixing.
Phase Changes
Explore the relationship between molecular motion, temperature, and phase changes. Compare the molecular structure of solids, liquids, and gases. Graph temperature changes as ice is melted and water is boiled. Find the effect of altitude on phase changes. The starting temperature, ice volume, altitude, and rate of heating or cooling can be adjusted.
Energy Conversion in a System
A falling cylinder is attached to a rotating propeller that stirs and heats the water in a beaker. The mass and height of the cylinder, as well as the quantity and initial temperature of water can be adjusted. The temperature of the water is measured as energy is converted from one form to another.
Unit 7: Equilibrium
Equilibrium and Concentration
Observe how reactants and products interact in reversible reactions. The initial amount of each substance can be manipulated, as well as the pressure on the chamber. The amounts, concentrations, and partial pressures of each reactant and product can be tracked over time as the reaction proceeds toward equilibrium.
Unit 8: Acids and Bases
