Across
- 3. speed at which light waves propagate through different materials
- 4. the same properties at every point
- 7. a material composed of antiparticles
- 9. mass of a unit volume of a material substance.
- 10. a quantum of electromagnetic radiation
- 11. the change in the frequency of a light wave depending on whether an object is moving towards or away from us
- 14. a physical quantity that expresses hot and cold or a measure of the average kinetic energy of the atoms or molecules in the system
- 15. the science of the origin and development of the universe.
Down
- 1. subatomic particle of the same mass as a proton but having a negative electric charge and oppositely directed magnetic moment.
- 2. the SI base unit of thermodynamic temperature
- 5. a contraction of the universe to a state of extremely high density and temperature
- 6. the density of matter that would be required to halt the expansion of the universe.
- 8. the progression of events from the past to the present into the future
- 12. the smallest unit of ordinary matter that forms a chemical element.
- 13. having uniform physical properties in all directions