1. (a)Cite the difference between atomic mass and atomic weight.
(b)Silicon has three naturally-occurring isotopes as shown in the table below. On the basis of this data, confirm that the average atomic weight of Si is 28.0854 amu.
|Silicon Isotope |Natural Abundance |Atomic mass of | | | |isotope (amu) |
|28Si |92.23 % |27.9769 |
|29Si |4.68 % |28.9765 |
|30Si |3.09 % |29.9738 |
2. (a)Cite two important quantum-mechanical concepts associated with the Bohr model of the atom.
(b)Cite two important additional refinements that resulted from the wave-mechanical atomic model.
3. Relative to electrons and electron states, what does each of the four quantum numbers specify?
4. Give the electron configurations for the following ions: P5+, P3-, Sn4+, Se2-, I- and Ni2+.
5. Potassium iodide (KI) exhibits predominantly ionic bonding. The K+ and I- ions have electron structures that are identical to which two inert gases?
6. Without consulting the periodic table, determine whether each of the electron configurations given below is an inert gas, a halogen, an alkali metal, an alkaline earth metal, or a transition metal. Justify your choices. a. 1s22s22p63s23p5
7. Calculate the force of attraction between a Ca2+ and an O2- ion, the centers of which are separated by a distance of 1.25 nm.
8. The net potential energy between two adjacent ions, EN, may be represented by the sum of the attractive energy, EA and the repulsive energy, ER; that is,
Calculate the bonding energy E0 in terms of the...