Ateacher wants to perform a classroom demonstration that illustrates both chemical and physical changes. which would be the best demonstration that she could use?

Identify which properties could correspond to solids, plasmas, or both. maintain a unique shape. collide infrequently with other particles. have very high velocities. conduct electricity. protons. have a low temperature. has long-range order.

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

650.j is the same amount of energy as? 2720cal1550cal650.cal2.72cal