20. write the noble gas electron configuration for iodine (i). then draw the electron dot structure for…

Explanation:

Step1: Identify the noble - gas core

Iodine (I) has an atomic number of 53. The nearest noble gas with a lower atomic number is krypton (Kr) which has an atomic number of 36.

Step2: Write the electron configuration after the noble - gas core

After the krypton core, we need to account for the remaining electrons. The remaining number of electrons is (53 - 36=17). The electron configuration after Kr is (4d^{10}5s^{2}5p^{5}). So the noble - gas electron configuration of iodine is ([Kr]4d^{10}5s^{2}5p^{5}).

Step3: Draw the electron - dot structure

The number of valence electrons of iodine is 7 (from (5s^{2}5p^{5})). We place the symbol 'I' in the center and then place 7 dots around it to represent the valence electrons.

Answer:

Noble - gas electron configuration: ([Kr]4d^{10}5s^{2}5p^{5}); Electron - dot structure: Place the symbol 'I' in the center and 7 dots around it.