1. DE Science Elementary Force, Motion, and Energy

2. Friction – The Big Ideas Friction is a force that resists the motion of two objects rubbing together. Friction reduces the motion produced by a force. Oily or greasy substances reduce friction on other objects. Rubber and similar substances increase friction. The roughness or smoothness of two surfaces rubbing against each other determines the amount of friction. Friction often produces heat.

3. Friction – Using DE Science Content Exploration: FrictionFriction Video: FrictionFriction Video: Friction on the Ground and in the AirFriction on the Ground and in the Air

4. Thermal Energy – The Big Ideas Adding heat to matter causes the motion of molecules in that matter to speed up. Heat is a form of energy. Heat energy can be produced by light being absorbed by a surface. Heat energy can be produced by the friction of two surfaces rubbing together. Heat energy can be produced by chemical reactions.

5. Thermal Energy – Using DE Science Content Exploration: Thermal EnergyThermal Energy Video: HeatHeat Video: Heat: The Flow of Energy from One Thing to AnotherHeat: The Flow of Energy from One Thing to Another

6. Waves – The Big Ideas Waves are motion energy flowing through matter. Energy is often transmitted as waves. Waves travel outward from their source. Some waves are visible, but others are too small to be seen.

7. Waves – Using DE Science Content Exploration: WavesWaves Video: Radiation and the SunRadiation and the Sun Video: Electromagnetic Waves and the Sun’s RaysElectromagnetic Waves and the Sun’s Rays

8. Sound Waves – The Big Ideas Sound is energy that travels in the form of waves away from a vibrating object. Sound waves travel through all three states of matter. Sound waves cannot travel through a vacuum, which has no matter.

9. Sound Waves – Using DE Science Content Exploration: Sound WavesSound Waves Video: How is Sound Made?How is Sound Made? Video: SoundSound

10. Light Energy – The Big Ideas Light is a form of energy. Light travels in electromagnetic waves. Frequency, wavelength, and amplitude are characteristics of light waves. Light travels faster than anything else in the universe. Light waves can travel through some solids, liquids, and gases. Light waves can travel through a vacuum.

11. Light Energy – Using DE Science Content Exploration: Light EnergyLight Energy Video: Light: A Visible Form of EnergyLight: A Visible Form of Energy Video: Properties of Light WavesProperties of Light Waves

12. Reflection – The Big Ideas Light waves are reflected evenly by a smooth shiny surface. Light waves are scattered unevenly by a rough surface.

13. Reflection – Using DE Science Content Exploration: ReflectionReflection Video: Light Reflection: Dependent on SurfaceLight Reflection: Dependent on Surface Video: Light Sources and ObservationsLight Sources and Observations

14. Refraction – The Big Ideas Light waves refract, or bend, as they pass through transparent materials. Refraction means that light bends as it travels from one transparent material into another. Lenses refract light. The shapes of lenses refract light in different ways. A convex lens is thicker in its middle, bending light rays that pass through it together to a focal point. A concave lens is thinner it its middle, spreading light rays apart as they pass through it. A prism refracts different wavelengths at different angles, producing a spectrum of color.

15. Refraction – Using DE Science Content Exploration: RefractionRefraction Video: Mirrors and LensesMirrors and Lenses Video: RefractionRefraction

16. Current Electricity – The Big Ideas Electricity flows through a circuit to light light bulbs and cause other things to work. An electric current is a steady flow of charged particles. Electrically charged particles moving in a current must have a closed circuit path. Circuits usually include wires made of metal and other materials that conduct electricity. Metals such as copper and iron readily conduct electricity and are used in wires to help the flow of electricity. Insulators, such as rubber and wood, conduct electricity very poorly. Electrical energy can be changed to other forms of energy, such as a toaster turning electrical energy into heat.

17. Current Electricity – Using DE Science Content Exploration: Electric Current Electric Current Video: CircuitsCircuits Video: Electrical FlowElectrical Flow