Atomic #-3 Symbol and Le structure Atomic Mass #= # of p+ = # of n= # of e-D

ow does probability ?t into the description of the atom?

Discuss briefly the difference between an orbit (as described by Bohr for hydrogen) and an orbital (as described by the more modern, wave mechanical picture of the atom).

6.106 When Bohr devised his model for the atom, was he using deductive or inductive reasoning? Explain your answer.

The energies of macroscopic objects, as well as those of microscopic objects, are quantized, but the effects of the quantization are not seen because the difference in energy between adjacent states is so small. Apply Bohr’s quantization of angular momentum to the revolution of Earth (mass6.01024kg) , which moves with a speed of 3.0104ms1 in a circular orbit (radius1.51011m) about the sun. The sun can be treated as fixed. Calculate the value of the quantum number n for the present state of the Earthsun system. What would be the effect of an increase in n by 1?

The energy needed to remove one electron from a gaseous potassium atom is only about two-thirds as much as that needed to remove one electron from a gaseous calcium atom, yet nearly three times as much energy as that needed to remove one electron from K+ as from Ca+ . What explanation can you give for this contrast? What do you expect to be the relation between the ionization energy of Ca+ and that of neutral K?

Using the periodic table and without looking at Table 7.3, write electron configurations for the following elements: (a) P (b) Zn (c) Zr (d) In (e) Pb (f) U Use the spdf and noble gas notations. When you have finished, check your answers with Table 7.3.

List the charges on hydrogen-like atoms whose nuclei are of the following elements. a lithium, b carbon, c iron, d samarium, e xenon, f francium, g uranium, h seaborgium

Spectroscopic studies of Li also show that Zeff(2p)=1.02 . Estimate the energy of the 2p orbital of Li. Calculate the average distance of the electron from the nucleus in the 2p orbital of Li. Comparing your results with those in Problem 13 shows that the energy values differ by about 50%, whereas the average distances are nearly equal. Explain this observation.

The helium ion He+ is a one-electron system whose wave functions and energy levels are obtained from those for H by changing the atomic number to Z=2 . Calculate the average distance of the electron from the nucleus in the 2s orbital and in the 2p orbital. Compare your results with those in Problem 11 and explain the difference.