The number of orbitals associated with quantum number n = 5, m_s = +$${1 \over 2}$$ is :

The electrons are more likely to be found :

The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are:

The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series are :