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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
Electronegativity decreases down the group due to the increase in atomic size. As you move down group 7, additional electron shells are added, which increases the distance between the nucleus and the bonding electrons. This results in greater shielding from the nuclear charge, causing the attraction of the nucleus for the bonding electrons to decrease.
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 the group due to the increase in the strength of London Dispersion Forces (LDFs) as the number of electrons in the molecules increases. With more electrons, the electron cloud becomes more polarizable, leading to stronger temporary dipoles and greater intermolecular attractions. As a result, more energy (in the form of heat) is required to overcome these forces, leading to higher boiling points.