The two most common isotopes of uranium are 235U and 238U. (a) Compare the number of proto...

The two most common isotopes of uranium are 235U and 238U. (a) Compare the number of protons, the number of electrons, and the number of neutrons in atoms of these two isotopes. (b) Using the periodic table in the front-inside cover, write the electron configuration for a U atom. (c) Compare your answer to part (b) to the electron configuration given in Figure How can you explain any differences between these two electron configurations?

▲ Figure Regions of the periodic table. The order in which electrons are added to orbitals is read left to right beginning in the top-left corner.

(d) 238U undergoes radioactive decay to 234Th. How many protons, electrons, and neutrons are gained or lost by the 238U atom during this process? (e) Examine the electron configuration for Th in Figure Are you surprised by what you find? Explain.

▲ Figure Outer-shell electron configurations of the elements.