NOAA
Noaa: Estuary Education: Read the Beach (Sand Science)
Geologist Dr. Jeff Warren shows how the beach is built and performs a "fizzy" experiment with beach sand to show evidence of its physical and chemical composition. [8:14]
Sophia Learning
Sophia: Neils Bohr
Learn about the Bohr model of the atom where the electrons exist in energy levels or shells. [2:50]