You are entirely forgiven for not knowing this, since they are not especially rare — cerium is about as common as copper. The problem is that they’re difficult to isolate and purify; it wouldn’t be ...

From Play-Doh to Barbie, major toy companies have long sought a foothold in the education marketplace by offering branded classroom materials and educational videos teachers can use. But now, one ...

From Play-Doh to Barbie, major toy companies have long sought a foothold in the education marketplace by offering branded classroom materials and educational videos teachers can use. But now, one ...