Nebraska - Science: Chemistry

Electron Configuration

Create the electron configuration of any element by filling electron orbitals. Determine the relationship between electron configuration and atomic radius. Discover trends in atomic radii across periods and down families/groups of the periodic table. 5 Minute Preview

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. 5 Minute Preview

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. 5 Minute Preview

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. 5 Minute Preview

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. 5 Minute Preview

Covalent Bonds

Choose a substance, and then move electrons between atoms to form covalent bonds and build molecules. Observe the orbits of shared electrons in single, double, and triple covalent bonds. Compare the completed molecules to the corresponding Lewis diagrams. 5 Minute Preview

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. 5 Minute Preview

Crumple Zones

Design a car to protect a test dummy in a collision. Adjust the length and stiffness of the crumple zone and the rigidity of the safety cell to determine how the car will deform during the crash. Add seat belts and/or airbags to prevent the dummy from hitting the steering wheel. Three different body types (sedan, SUV, and subcompact) are available and a wide range of crash speeds can be used. 5 Minute Preview

GMOs and the Environment

In this follow-up to the Genetic Engineering Gizmo, explore how farmers can maximize yield while limiting ecosystem damage using genetically modified corn. Choose the corn type to plant and the amount of herbicide and insecticide to use, then measure corn yields and monitor wildlife populations and diversity. Observe the long-term effects of pollutants on a nearby stream ecosystem. 5 Minute Preview

Genetic Engineering

Use genetic engineering techniques to create corn plants resistant to insect pests or tolerant of herbicides. Identify useful genes from bacteria, insert the desired gene into a corn plant, and then compare the modified plant to a control plant in a lab setting. 5 Minute Preview

Nitrogen Cycle - High School

An infant on a farm has blue baby syndrome. As an EPA environmental engineer, students must find the cause of the baby's illness. Using environment data, students learn the importance of the nitrogen cycle and how human factors can impact nature. Video Preview

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. 5 Minute Preview

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. 5 Minute Preview

Isotopes

Explore what isotopes are by adding protons and neutrons to the nucleus of an atom. Plot both stable and radioactive isotopes on a graph of neutrons vs. protons, and explore how the neutron:proton ratio of stable isotopes changes from lighter to heavier elements. 5 Minute Preview

Nuclear Decay

Observe the five main types of nuclear decay: alpha decay, beta decay, gamma decay, positron emission, and electron capture. Write nuclear equations by determining the mass numbers and atomic numbers of daughter products and emitted particles. 5 Minute Preview

Nuclear Reactions

Explore examples of nuclear fusion and fission reactions. Follow the steps of the proton-proton chain, CNO cycle, and fission of uranium-235. Write balanced nuclear equations for each step, and compare the energy produced in each process. 5 Minute Preview

Diffusion

Explore the motion of particles as they bounce around from one side of a room to the other through an adjustable gap or partition. The mass of the particles can be adjusted, as well as the temperature of the room and the initial number of particles. In a real-world context, this can be used to learn about how odors travel, fluids move through gaps, the thermodynamics of gases, and statistical probability. 5 Minute Preview

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. 5 Minute Preview

Energy of a Pendulum

Perform experiments with a pendulum to gain an understanding of energy conservation in simple harmonic motion. The mass, length, and gravitational acceleration of the pendulum can be adjusted, as well as the initial angle. The potential energy, kinetic energy, and total energy of the oscillating pendulum can be displayed on a table, bar chart or graph. 5 Minute Preview

Inclined Plane - Rolling Objects

Observe and compare objects of different shapes as they roll or slide down an inclined plane. Compare the percentages of translational and rotational kinetic energy for each object, and see how this affects how quickly each object moves. The slope of each ramp can be adjusted, and a variety of materials can be used for the objects and ramps. 5 Minute Preview

Inclined Plane - Simple Machine

Investigate how an inclined plane redirects and reduces the force pulling a brick downward, with or without friction. A toy car can apply a variable upward force on the brick, and the mechanical advantage and efficiency of the plane can be determined. A graph of force versus distance illustrates the concept of work. 5 Minute Preview

Inclined Plane - Sliding Objects

Investigate the energy and motion of a block sliding down an inclined plane, with or without friction. The ramp angle can be varied and a variety of materials for the block and ramp can be used. Potential and kinetic energy are reported as the block slides down the ramp. Two experiments can be run simultaneously to compare results as factors are varied. 5 Minute Preview

Crumple Zones

Design a car to protect a test dummy in a collision. Adjust the length and stiffness of the crumple zone and the rigidity of the safety cell to determine how the car will deform during the crash. Add seat belts and/or airbags to prevent the dummy from hitting the steering wheel. Three different body types (sedan, SUV, and subcompact) are available and a wide range of crash speeds can be used. 5 Minute Preview

GMOs and the Environment

In this follow-up to the Genetic Engineering Gizmo, explore how farmers can maximize yield while limiting ecosystem damage using genetically modified corn. Choose the corn type to plant and the amount of herbicide and insecticide to use, then measure corn yields and monitor wildlife populations and diversity. Observe the long-term effects of pollutants on a nearby stream ecosystem. 5 Minute Preview

Genetic Engineering

Use genetic engineering techniques to create corn plants resistant to insect pests or tolerant of herbicides. Identify useful genes from bacteria, insert the desired gene into a corn plant, and then compare the modified plant to a control plant in a lab setting. 5 Minute Preview

Nitrogen Cycle - High School

An infant on a farm has blue baby syndrome. As an EPA environmental engineer, students must find the cause of the baby's illness. Using environment data, students learn the importance of the nitrogen cycle and how human factors can impact nature. Video Preview

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. 5 Minute Preview

Equilibrium and Pressure

Observe how reactants and products interact in reversible reactions. The amounts of each substance can be manipulated, as well as the pressure on the chamber. This lesson focuses on partial pressures, Dalton's law, and Le Chatelier's principle. 5 Minute Preview

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. 5 Minute Preview

Limiting Reactants

Explore the concepts of limiting reactants, excess reactants, and theoretical yield in a chemical reaction. Select one of two different reactions, choose the number of molecules of each reactant, and then observe the products created and the reactants left over. 5 Minute Preview

Stoichiometry

Solve problems in chemistry using dimensional analysis. Select appropriate tiles so that units in the question are converted into units of the answer. Tiles can be flipped, and answers can be calculated once the appropriate unit conversions have been applied. 5 Minute Preview

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. 5 Minute Preview

Covalent Bonds

Choose a substance, and then move electrons between atoms to form covalent bonds and build molecules. Observe the orbits of shared electrons in single, double, and triple covalent bonds. Compare the completed molecules to the corresponding Lewis diagrams. 5 Minute Preview

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. 5 Minute Preview

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. 5 Minute Preview