Chemical Bonding And Molecular Structure

In the H O (water) molecule, the oxygen atom forms two single bonds with hydrogen atoms and has two lone pairs of electrons. This leads to a bent or V-shaped molecular geometry, not linear or trigonal planar. Due to the repulsion from lone pairs, the bond angle is reduced from the ideal tetrahedral angle (109 28') to approximately 104 31'. This value is experimentally determined and is a characteristic property of the water molecule's shape.

The correct option is (D):

Linus Pauling proposed the concept of electronegativity based on the bond energies of atoms in molecules. He observed that the actual bond energy of a heteronuclear bond (between different atoms) is often higher than the average of the bond energies of homonuclear bonds. This additional stabilization was attributed to the difference in electronegativity between the atoms. Therefore, Pauling’s electronegativity values are based on bond energy.

The correct option is (D): bond energy

Correct answer: catenation

Explanation:
Catenation is the ability of an element to form long chains by bonding with atoms of the same element. This property is especially strong in carbon, allowing it to form long straight, branched, or cyclic chains. It is responsible for the vast number of organic compounds.

- Allotropy refers to the existence of an element in more than one physical form (e.g., diamond and graphite for carbon).
- Hybridization is the mixing of atomic orbitals to form new hybrid orbitals.
- Isomerism refers to compounds with the same molecular formula but different structures.

So, the correct term is catenation.

Chlorine is a halogen, located in group 17 of the periodic table.

Halogens have 7 valence electrons and tend to gain one electron to achieve a stable noble gas configuration (8 valence electrons). When an atom gains an electron, it becomes negatively charged because it now has more electrons than protons.

A negatively charged ion is called an anion. When an atom loses an electron, it becomes positively charged because it now has fewer electrons than protons. A positively charged ion is called a *cation*.

Since chlorine gains an electron to become stable, it becomes an anion.

Linus Pauling proposed the concept of hybridization.

Linus Pauling was a renowned chemist who made significant contributions to the field of chemistry. He is best known for his work on the nature of the chemical bond and the structure of molecules. One of his key contributions was the development of the concept of hybridization, which explains how atomic orbitals mix to form new hybrid orbitals that can participate in bonding. This concept is fundamental in understanding the shapes and structures of molecules.

While Linus Pauling did not propose the concepts of ionic bonds, hydrogen bonds, or covalent bonds, he did contribute significantly to the understanding and development of these concepts through his work on chemical bonding and molecular structure.

The notation tells us that the element X has an atomic number of 13. The atomic number corresponds to the number of protons and, in a neutral atom, also the number of electrons. Element 13 is aluminum (Al).

Aluminum is in group 13 of the periodic table. Elements in group 13 have 3 valence electrons. To achieve a stable electron configuration, aluminum tends to lose these 3 valence electrons. When an atom loses electrons, it becomes a positively charged ion (a cation).

Since aluminum loses 3 electrons, its charge becomes +3.