f. g. a. The minimum in potential energy corresponding to the interaction between the repulsive and attractive potential energies between atoms coming together in proximity corresponds to what important bonding property? b. Atomic structures forming tetrahedrons involved in covalent bonding have orbitals aligned at 109.5-what is the underlying physics that accounts for this observation of bonding angle? - - c. CH4 methane experiences covalent bonds typically very strong bonds. However, it is none the less a gas with low melting point in its solid form. Explain. d. Diamond experiences covalent bonds between carbon atoms in an all carbon matrix leading to strong mechanical properties, high melting point, and electrical insulating properties. - It has none the less excellent thermal conductivity properties. Explain. e. What is a very practical test to determine if you have a covalently or ionically bonded crystal. Why does crystalline Argon have a low melting point? Tungsten (W) is often used as a source of an electron beam in x-ray diffraction tubes and scanning electron microscopes where a large current is passed through a thin W wire. What is this process called to generate the electrons?