Fluorine, chlroine, bromine and iodine are placed in the same group (17) of the periodic table, because

Options

A. They are non-metals
B. They are electronegative
C. Their atoms are generally univalent
D. They have 7 electrons in the outermost shell of their atom

Explanation

**Step-by-Step Solution:**

1. **Identify the Elements**: The elements in question are Fluorine (F), Chlorine (Cl), Bromine (Br), and Iodine (I). These elements are all located in Group 17 of the periodic table.

2. **Group Classification**: Group 17 is known as the Halogens. The classification of these elements into the same group is due to their similar chemical properties.

3. **Outermost Electron Configuration**: Each of these halogens has a similar outermost electron configuration.
- Fluorine: 1s² 2s² 2p⁵ (7 electrons in the outermost shell)
- Chlorine: 1s² 2s² 2p⁶ 3s² 3p⁵ (7 electrons in the outermost shell)
- Bromine: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁵ (7 electrons in the outermost shell)
- Iodine: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁵ (7 electrons in the outermost shell)

4. **Valence Electrons**: All these elements have 7 valence electrons. This is a key characteristic that defines their chemical behavior, particularly their tendency to gain one electron to achieve a stable octet configuration.

5. **Chemical Properties**: Due to the presence of 7 valence electrons, these elements exhibit similar chemical properties such as high electronegativity and the ability to form negative ions (anions) by gaining an electron.

6. **Conclusion**: Therefore, Fluorine, Chlorine, Bromine, and Iodine are placed in the same group (Group 17) of the periodic table because they share similar outermost electron configurations and exhibit similar chemical properties as halogens.

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