Verified Answer :
- Nitrogen contributes 5 valence electrons, and three hydrogen atoms contribute 3, totaling 8 electrons.
- The nitrogen atom forms three covalent bonds with hydrogen, utilizing 6 of these electrons, with the remaining 2 forming a lone pair.
- Each N-H bond consists of a single shared pair of electrons, identifying them as single bonds.
- Since no double or triple bonds are present, the molecule contains only single bonds.
- The final answer is true. \(\boxed{\text{true}}\)
Explanation
- Analyzing Valence Electrons and Molecular Composition
The ammonia molecule, denoted as \(NH_3\), consists of one central nitrogen atom bonded to three hydrogen atoms. To determine the nature of these bonds, we first identify the valence electrons of each atom. Nitrogen, with an atomic number of 7, has a valence electron configuration of \(2s^2 2p^3\), providing 5 valence electrons. Each hydrogen atom has 1 valence electron. Therefore, the total number of valence electrons available for bonding in the molecule is \(5 + (3 \times 1) = 8\) electrons.
- Determining the Lewis Structure of Ammonia
In the Lewis structure of ammonia, the nitrogen atom occupies the center and forms three separate covalent bonds, one with each hydrogen atom. A single covalent bond is formed by the sharing of one pair of electrons between two atoms. Since there are three hydrogen atoms, there are three N-H bonds in total. These three bonds account for \(3 \times 2 = 6\) of the available valence electrons. The remaining \(8 - 6 = 2\) electrons form a lone pair on the nitrogen atom, which does not participate in bonding.
- Conclusion on Bonding Type in Ammonia
Each of the three bonds connecting the nitrogen atom to the hydrogen atoms is formed by exactly one shared pair of electrons, which defines a single bond. There are no additional shared electron pairs between any of the atoms that would constitute a double or triple bond. Consequently, the ammonia molecule consists exclusively of three single N-H bonds. Thus, the statement that the ammonia molecule contains all single bonds is correct.
Examples
Understanding molecular bonding is essential in fields like chemistry and pharmacology. For instance, in drug design, determining whether bonds are single, double, or triple helps researchers predict the rigidity and geometry of a molecule. Since ammonia has all single N-H bonds, it adopts a trigonal pyramidal shape rather than a flat one, which influences how it interacts with other molecules in chemical reactions, such as acting as a base in industrial processes.