Which statement about iodide ions is correct?
They reduce concentrated sulfuric acid to form sulfur dioxide as the only reduction product.
They form a yellow precipitate with silver nitrate solution that is insoluble in concentrated aqueous ammonia.
They have the electron configuration 1s22s22p63s23p63d104s24p64d105s25p51s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 4d^{10} 5s^2 5p^51s22s22p63s23p63d104s24p64d105s25p5.
They are oxidized to iodine by reaction with aqueous sodium chloride.
