In this atomic model, energy levels are thought of as clouds surrounding the nucleus. They are sometimes referred to as orbitals. Which model is described? A) Bohr B) Rutherford C) Schrödinger D) Quantum Mechanical

Explanation for basic character?

Calculate the number of molecules present in 0.750 mol of mgo.

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms