Question

The strongest bond is present in:
A.\[{\text{B}}{{\text{r}}_2}\]
B.\[{{\text{I}}_2}\]
C.\[{\text{C}}{{\text{l}}_2}\]
D.\[{{\text{F}}_2}\]

Answer 1

Hint: Strength depends on the atoms or molecules present. Electronegativity and the size of the atom are the major factors that affect here. There is an anomalous behavior also.

Complete step by step solution:
In the periodic table, the elements show a similarity in some properties, which is known as periodic trends. These are shown concerning their groups and periods. Down the group, atomic radii increases, i.e. the size of the atom increases. Top to bottom, the atomic size increases, and the number of shells also increases. Therefore the electrons in the valence shell are very distant from the nucleus. So it is very easy to lose electrons from the valence shell and become electropositive in nature.
The given elements are elements in group 17. Among these elements, fluorine is the smallest element than others. Thus fluorine is the most electronegative element among these. Bond strength increases with an increase in electronegativity. Because more electrons are present in the valence shell. So there would be greater attraction towards the nucleus occurs.But fluorine has an anomalous behavior. Fluorine is an element of smaller size than other halogens. Therefore it shows a repulsion between the electrons. Thus it is unstable.
Therefore \[{\text{C}}{{\text{l}}_2}\] has more bond strength.

Hence option C is correct.

Additional information:
${\text{C}}{{\text{l}}_2}\rangle {\text{B}}{{\text{r}}_2}\rangle {{\text{F}}_2}\rangle {{\text{I}}_2}$

This is the trend shown in the halogens group. Bond strength generally increases with increase in p orbital. Since iodine is very large in size, it does not have any nuclear charge in it.

Note: Electronegativity increases from left to right. From left to right, the number of electrons increases. Therefore it has a strong force of attraction towards the nucleus from these electrons. But from top to bottom, the number of shells is increasing. So the electrons are more distant from the nucleus. Therefore it has less force of attraction towards the nucleus.