meteor

/Tag: meteor

What is iron? Atoms, elements, chemistry

By |2018-04-24T14:46:24-07:00June 2nd, 2017|Chemistry|

Diagram of an iron atom When a red giant star finishes changing all of its helium into carbon and oxygen, it then starts to turn the carbon and oxygen atoms into iron atoms. Iron is the heaviest kind of atom that a star can make, so when a star has made most of its carbon and oxygen [...]

What are dinosaurs? Evolution and Biology

By |2019-05-08T08:46:44-07:00May 26th, 2017|Biology|

A dinosaur skeleton: evolution of dinosaurs When did dinosaurs evolve? The first dinosaurs evolved out of earlier types of chordate reptiles about 230 million years ago, on the big land mass called Pangaea. Earlier chordates More about reptiles The Triassic period All our biology articles Cold-blooded or warm-blooded? Dinosaur eggs: evolution of [...]

What are Mammals – Biology

By |2018-04-21T11:56:43-07:00May 26th, 2017|Biology|

Rat from New Zealand About 200 million years ago, when all the land on Earth was stuck together in one big continent called Pangaea, some animals related to reptiles living on Pangaea gradually evolved into a new group called mammals (MAMM-elz). The mammals were different from the earlier reptiles in several ways. First, [...]