Answer two questions in this section.

 

1. Should we expect to be a stable molecule in the gas phase? Explain briefly. [3 marks]
2. Element 118 has apparently recently been made at the Lawrence Berkeley National Laboratory in California by fusing atoms of krypton and lead. Based on quantum mechanical principles, the chemical properties of this new element should most closely resemble those of which existing element(s)? Explain. [3 marks]
3. Explain the meaning of the negative sign in the equation for the energy of a hydrogenic atom. [3 marks]
4. Briefly describe how the radial probability density corresponding to a given atomic orbital can be calculated. [3 marks]