The table below shows some properties of germanium, discovered in 1886 by Clemens Winkler. Germanium was Mendeleev's predicted eka-silicon. Why did its discovery support Mendeleev's ideas?
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Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.

The amount of potential energy possessed by an elevated object is equal to what?