Answer:
Step-by-step explanation:
**(a) Electronegativity Values Without Units:**
The values given for electronegativity in Table 7 of the IB Chemistry Data Booklet are based on various scales, most commonly the Pauling scale. Electronegativity is a relative measure of an element's ability to attract electrons in a chemical bond. The values are not tied to a specific unit because electronegativity is a comparative property. It represents the tendency of an atom to attract electrons relative to other atoms in a compound, rather than an absolute property that can be measured in specific units like length or mass.
**(b) Elements with Highest and Lowest Electronegativity:**
The elements with the greatest values for electronegativity tend to be nonmetals, particularly those from the upper right corner of the periodic table. Elements with the lowest electronegativity values are typically metals, especially those from the lower left corner of the periodic table.
Four elements with the highest electronegativity values:
1. Fluorine (F)
2. Oxygen (O)
3. Nitrogen (N)
4. Chlorine (Cl)
Four elements with the lowest electronegativity values:
1. Cesium (Cs)
2. Francium (Fr)
3. Barium (Ba)
4. Strontium (Sr)
**(c) Types of Bonding:**
(i) When two elements with very high electronegativity values bond, they are likely to form a **covalent bond**. Covalent bonds involve the sharing of electrons between atoms, and elements with similar electronegativities share electrons relatively equally.
(ii) When an element with a very high electronegativity value bonds with an element with a very low electronegativity value, they are likely to form an **ionic bond**. Ionic bonds occur when one element (with a high electronegativity) donates electrons to another element (with a low electronegativity), resulting in the formation of positively and negatively charged ions that are attracted to each other due to their opposite charges.