What is the maximum number of electrons which can reside in the 2p orbitals? 

Consider the following sketch of the interaction energy for two atoms as a function of distance between the atoms.

Label e) refers to the point where the interaction energy is lowest and shows how the stable bond length is calculated.  At this point ____________

How many 3s orbitals exist?

Consider the energy level diagram sketch below.

Which of the transitions, a) - e), represents a hydrogen atom in an excited state emitting light and ending up in its ground state?

What wavelength corresponds to the boundary between visible and IR radiation.

An atom is in its ground state if: 

Which wavelength corresponds to the boundary between UV and visible radiation?

The partial pressure of O₂ in the atmosphere at sea level is 21.3 kPa. What is the partial pressure of O₂ on the top of a mountain, where the atmospheric pressure is 84.9 kPa?

[Atmospheric pressure at sea level is 101.3 kPa.]

How many atomic orbitals have the principal quantum number n = 2?

What is the maximum number of electrons that can be accommodated, in total, for all of the 3d orbitals?