Halogens are very reactive and have only one electron less than noble gases.
Group 17 Elements
The group 17 elements include fluorine(F), chlorine (Cl), bromine(Br), iodine(I) and astatine(At) from the top to the bottom. They are called “halogens” because they give salts when they react with metals.
- The valence shell electronic configuration of these electrons is ns2np5.
- The nuclear and atomic radii of these elements keep on increasing as we move down the group.
- These elements have higher ionization enthalpy.
- The electron gain enthalpy of these elements becomes less negative upon moving down the group.
- Fluorine has lesser enthalpy than chlorine.
- The halogens exhibit high electro-negativity values.
- The group 17 elements have different physical states. For example, Fluorine and Chlorine are gases. On the other hand, Bromine is a liquid, and Iodine is solid.
- These elements have a variety of colours. For example, fluorine is pale yellow in colour; Iodine is dark violet in colour.
- Fluorine and Chlorine are soluble in water; on the other hand, Fluorine and Chlorine are soluble in water.
- The melting and boiling points of these elements increase as we move down the group from Fluorine to Iodine.
- All the halogens are great oxidizing agents.
- All halogens react with hydrogen and produce acidic hydrogen halides.
- Halogens react with oxygen to form oxides.