Excerpts from Topics in Science Volume 1

The opening screen of topics in Science Volume 1 provides access to four sections. Acceleration section describes the change in velocity, the acceleration using a scater animation. Several cell components are descibed in Cell components. The story, the basic structure of DNA and animation of DNA duplication are shown next. Ionic bond and ionic lattice building is discussed under Ionic bond formation.

 

A scater begins at the top of the slope with a starting speed of zero and a constant gravitational acceleration. As he moves downwards his speed increases until he reaches the plateau. Here the acceleration is zero and his speed is constant. As he begins to climb up the apposite wall, the gravitational pull applies a negative acceleration which slows his speed to zero at the top.

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Sodium (blue) gives away it's single electron and Chlorine (yellow)adds that electron to its seven valence electrons. Sodium becomes positively charged (a cation) while Chlorine becomes negatively charged (an anion). Both atoms have now a ‘fully' occupied outer electron layer which is the stable configuration according to the octet rule. During lattice formation Sodium and Chlorine atoms are joining and forming three dimensional network of ionic bonds and ions. These lattices have usually a characteristic geometry, often cubic as in the case of Sodium Chloride (NaCl).

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Scanning Electron Microscope image of NaCl crystals, magnified 50x