Question:
Answer the following questions about the element selenium.
a) Samples of natural selenium contain six stable isotopes. In terms of atomic structure, explain what these isotopes have in common and how they differ.
b) Write the complete electron configuration (i.e. 1s2) for a selenium atom in the ground state. Indicate the number of unpaired electrons in the ground-state atom and how it may react in a chemical reaction. Explain your reasoning.
c) In terms of atomic structure, explain why the first ionization energy of selenium is less than that of bromine, and greater than that of tellurium.
d) Selenium reacts with fluorine to form selenium tetrafluoride. Draw the complete Lewis electron-dot structure for SeF4 and sketch the molecular structure. Indicate whether the molecule is polar or nonpolar, and justify your answer.