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Ordovician Period – limestone and liverwort

By |2018-04-21T11:56:38+00:00June 24th, 2017|Geology|

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 died, because of some catastrophe that we don't know much about. This catastrophe marks the beginning of the Ordovician period. Limestone formed Sea [...]

Calcium project – Chalk and lemon juice – Chemistry

By |2018-04-16T17:38:03+00:00June 1st, 2017|Chemistry|

Need chalk? Buy chalk Take a piece of regular white chalk, like for writing on a blackboard. Make sure the chalk is calcium carbonate like the kind in the picture and not made of plaster of paris. Drop the chalk in a cup of vinegar or lemon juice. Vinegar is made of water [...]

Calcium – Atoms and Chemistry

By |2018-04-16T14:37:53+00:00June 1st, 2017|Biology, Chemistry|

Chalk cliff (made of calcium) in Cottonwood Canyon, Pueblo, Colorado When a star is on the way to converting all of its carbon and oxygen atoms into iron, calcium is one kind of atom it makes along the way. One atom of calcium has 20 protons and 20 electrons (and 20 neutrons). Calcium is a [...]

Eggs – Evolution and Biology

By |2018-04-16T10:33:22+00:00May 29th, 2017|Biology|

Fish eggs The earliest living creatures made babies by dividing themselves in half, so that one cell became two cells. But about 1.4 billion years ago, some creatures with more than one cell began to develop specialized cells that could combine with the cells from another creature to make a new creature. These were [...]