The elements chlorine and iodine have similar chemical properties because they . Group of answer choices have the same number of stable isotopes are both metals and can easily lose electrons to form compounds None of these have the same number of electrons in their outer energy levels are in the same chemical period

Have the same number of electrons in their outer energy levels

Explanation:

Elements in the same group have similar chemical properties because they have the same number of valence electron(s) in their outermost shell.

Chlorine and Iodine have similar chemical properties because they have the same number of valence electron in their outermost shell. This can be seen from their electronic configuration as shown below:

Cl (17) => 1s² 2s²2p⁶ 3s²3p⁵

I (53) => [Kr] 4d¹⁰ 5s²5p⁵

From the above illustration:

Outer shell of Cl (3s²3p⁵) = 2 + 5 = 7 electrons

Outer shell of I (5s²5p⁵) = 2 + 5 = 7 electrons

Since they have the same number of valence electrons, therefore, they will have similar chemical properties.