Continue to project the image Periodic table of energy levels for elements 1–20 and have students look at their activity sheets to find patterns in the number of electrons within each energy level.

"Understanding these cosmic rays allows us to unveil big particle accelerators in the universe that are often associated with the most violent phenomena." After over a decade of meticulous data ...

Scientists analyzed coal ash from power plants across the United States and found it could contain up to 11 million tons of rare earth elements — nearly eight times the amount the US has in ...