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The elements of group 7 in the periodic table are known as the halogens - Scottish Highers Chemistry - Question 1 - 2018
Question 1
The elements of group 7 in the periodic table are known as the halogens. (a) Going down group 7 the electronegativity of the halogens decreases. (i) State what is ... show full transcript
Worked Solution & Example Answer:The elements of group 7 in the periodic table are known as the halogens - Scottish Highers Chemistry - Question 1 - 2018
Step 1
Step 2
Explain why electronegativity values decrease going down group 7.
Answer
As we move down group 7, the number of electron shells increases, leading to more shielding of the nucleus. This increased distance between the nucleus and the outer electrons reduces the effective nuclear charge felt by these electrons, resulting in lower electronegativity.
Step 3
Explain fully why the boiling points of the halogens increase going down group 7.
Answer
The boiling points of the halogens increase down group 7 due to the increase in the strength of van der Waals forces. As the size of the halogen atoms increases, they possess more electrons, leading to stronger London dispersion forces (LDFs) between the molecules. These intermolecular forces must be overcome for the molecules to change from liquid to gas, hence a higher boiling point.