Tag: group 17 elements - properties

Lime water is calcium hydroxide and is a base so it turns phenolphthalein solution (an indicator) pink.

Fluorine is the most electronegative in halogen family so it has oxidation number of -1 in all its compounds but Cl,Br and I are less electronegative so these elements prepare compounds with oxidation number of +1,+3,+5 and +7.

Electronegativity is a chemical property that describes the tendency of the atom to attract electrons towards itself.

Both Assertion and Reason are true and the Reason is the correct explanation of the Assertion. 

Electron Affinity: decreases down the group. Since the atomic size increases down the group, electron affinity generally decreases$ ( I < Br < F < Cl)$. An electron will not be as attracted to the nucleus, resulting in a low electron affinity. However, fluorine has a lower electron affinity than chlorine.

Germanium forms tetrahalides with all halogens except astatine and forms dihalides with all halogens except bromine and astatine.

Chalcogens are chemical elements in group 16 of the periodic table. Germanium bonds to all natural single chalcogens except polonium.

As we move down the group the metallic character increases which impart lustrousness to the elements.

As the atomic size of the Florine is less it has more nuclear charge. So it requires more energy to remove the electron from its outer most orbit. So Florine has high ionization enthalpy and as we move down the group size increases nuclear charge decreases hence Ionization potential.

Florine is most electronegative than the other elements of that group because it has less atomic size so it attracts electrons more towards itself (Electronegativity).