Which orbital is the first be filled in any atom? Why?

Compare the configurations below with two electrons located in p orbitals. Which would be the most stable (have the lowest energy)? Which would be the least stable? Explain your answers.

The spectra of hydrogen and of calcium are shown in Figure 6.13. What causes the lines in these spectra? Why are the colors of the lines different? Suggest a reason for the observation that the spectrum of calcium is more complicated than the spectrum of hydrogen.

Which statement is true of the quantum mechanical model, but not of the Bohr model? a. Electrons orbit the nucleus in simple circular orbits, just like planets orbit the Sun. b. The exact path that an electron follows within an atom cannot be specified. c. The electron is attracted to the nucleus of the atom.

Why was Bohr's theory for the hydrogen atom initially accepted, and why was it ultimately discarded?

What additional information do we need to answer the question Which ion has the electron configuration 1s22s22p63s23p6 ?

Determine whether each statement that follows is true or false: a Electron energies are quantized in excited states but not in the ground state. b Line spectra of the elements are experimental evidence of the quantization of electron energies. c Energy is released as an electron passes from ground state to an excited state. d The energy of an electron may be between two quantized energy levels. e The Bohr model explanation of line spectra is still thought to be correct. f The quantum mechanical model of the atom describes orbitals in which electrons travel around the nucleus. g Orbitals are regions in which there is a high probability of finding an electron. h All energy sublevels have the same number of orbitals. i The 3p orbitals of an atom are larger than its 2p orbitals but smaller than its 4p orbitals. j At a given sublevel, the maximum number of d electrons is 5. k The halogens are found in Group 7A/17 of the periodic table. l The dot structure of the alkaline earths is X, where X is the symbol of element in the family. m Stable ions formed by alkaline earth metals are isoelectronic with noble gas atoms. n Atomic numbers 23 and 45 both belong to transition elements. o Atomic number 52, 35, and 18 are arranged in order of increasing atomic size. p Atomic number 7, 16, and 35 are all nonmetals.

Suppose that the spin quantum number could have the values 12,0 and 12 . Assuming that the rules governing the values of the other quantum numbers and the order of filling sublevels were unchanged, (a) what would be the electron capacity of an s sublevel? a p sublevel? a d sublevel? (b) how many electrons could fit in the n=3 level? (c) what would be the electron configuration of the element with atomic number 8? 17?