Ordovician Period – limestone and liverwort
The Ordovician period saw the evolution of the octopus At the end of the Cambrian period, about 488 million years ago, most of the plants and animals living on Earth [...]
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06, 2017
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06, 2017
Calcium project – Chalk and lemon juice – Chemistry
Need chalk? Buy chalk Chalk has calcium in it Take a piece of regular white chalk, like for writing on a blackboard. Make sure the chalk is calcium carbonate like [...]
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06, 2017
Calcium – Atoms and Chemistry
Chalk cliff (made of calcium atoms) in Cottonwood Canyon, Pueblo, Colorado What is calcium? When a star is on the way to converting all of its carbon and oxygen atoms into [...]
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05, 2017
Eggs – Evolution and Biology
Fish eggs: Egg evolution starts with soft eggs like these When did the first eggs evolve? The earliest living creatures made babies by dividing themselves in half, so that one [...]
