Which of the following statements concerning benzene is corr…

Which of the following statements concerning benzene is correct? I.   Benzene adds Br2 to retain the cyclic conjugation II.  All the carbon atoms are sp2 hybridized III. The heat of hydrogenation is more negative than we might expect for a conjugated cyclic  triene

A radiograph taken during an upper GI series demonstrates po…

A radiograph taken during an upper GI series demonstrates poor visibility of the gastric mucosa. The following factors were used: 80 kV, 30 mAs, 1/40-second exposure time, high-speed image receptors. Barium sulfate was used during the procedure. Which of the following factors needs to be modified during the repeat exposure?