Isomerism

• Option 1: Isotopes - This is incorrect. Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Since carbon and nitrogen are different elements, they cannot be isotopes of each other.
• Option 2: Isomers - This is incorrect. Isomers are molecules that have the same molecular formula but different structural arrangements. This concept does not apply to atoms of different elements like carbon and nitrogen.
• Option 3: Isotones - This is incorrect. Isotones are atoms of different elements that have the same number of neutrons. The number of neutrons in carbon-13 and nitrogen-14 are different, so they are not isotones.
• Option 4: Isobars - This is the correct answer. Isobars are atoms of different elements that have the same mass number but different atomic numbers. (Nitrogen-14) have the same total number of protons and neutrons, making them isobars.

Explanation:

The atoms of are considered isobars because they have the same mass number (13 for C-13 and 14 for N-14), but different atomic numbers (6 for carbon and 7 for nitrogen). Isobars are atoms of different elements that have the same mass number but different atomic numbers.

• Option 1: Isobars - This is the correct answer. Ar-40 and Ca-40 are isobars because they have the same mass number (40) but different atomic numbers (18 for Ar and 20 for Ca). Isobars are atoms of different elements that have the same mass number.
• Option 2: Isomers - This is incorrect. Isomers are molecules with the same molecular formula but different structural arrangements, which is not applicable to the case of Ar and Ca.
• Option 3: Isotopes - This is incorrect. Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons. Ar and Ca are different elements, so they cannot be isotopes of each other.
• Option 4: Isotones - This is incorrect. Isotones are atoms of different elements that have the same number of neutrons but different atomic numbers. Ar and Ca do not fit this definition because their numbers of neutrons are different.

Explanation:

Ar-40 and Ca-40 are considered isobars because they have the same mass number (40) but different atomic numbers (18 for Ar and 20 for Ca). Isobars are atoms of different elements that share the same mass number but have different atomic numbers.

• Option 1: Same mass number - This is incorrect. Isotones do not have the same mass number; they have the same number of neutrons but different mass numbers, because the number of protons (and thus the atomic number) is different.
• Option 2: Same atomic number - This is incorrect. Isotones are atoms of different elements, so they must have different atomic numbers (the number of protons). Having the same atomic number refers to isotopes, not isotones.
• Option 3: Same number of neutrons - This is the correct answer. Isotones are atoms of different elements that have the same number of neutrons but different atomic numbers (and thus different mass numbers).
• Option 4: Same number of electrons - This is incorrect. The number of electrons in isotones can vary depending on the ionization state, and it is not a defining characteristic of isotones.

Explanation:

Isotones are atoms of different elements that have the same number of neutrons but different atomic numbers and mass numbers. For example, carbon-14 (C-14) and nitrogen-15 (N-15) are isotones because they both have 8 neutrons, but they differ in the number of protons (atomic number) and thus belong to different elements.

• Option 1: Benzene - This is incorrect. Benzene (C₆H₆) has a 1:1 ratio of carbon to hydrogen atoms, which may appear complex due to its aromatic ring structure, but it still follows a simple atomic ratio of 1:1 in terms of carbon and hydrogen atoms.
• Option 2: Acetylene - This is incorrect. Acetylene (C₂H₂) follows a simple atomic ratio of 1:1 for carbon to hydrogen atoms, which makes it a straightforward molecule with a simple ratio of atoms.
• Option 3: Hydrogen - This is incorrect. Hydrogen (H₂) is a simple diatomic molecule with a 1:1 atomic ratio of hydrogen atoms.
• Option 4: Sucrose - This is the correct answer. Sucrose (C₁₂H₂₂O₁₁) does not follow a simple atomic ratio due to its more complex molecular structure. While the ratio of carbon to hydrogen to oxygen in sucrose is a whole number (12:22:11), it is considered more intricate because of the way the atoms are bonded in the molecule. The atomic arrangement in sucrose involves multiple functional groups and glycosidic linkages between monosaccharide units (glucose and fructose), which makes the ratio appear more complex compared to simple molecular compounds like acetylene or benzene.

Detailed Explanation:

Sucrose is a disaccharide made up of two monosaccharides: glucose and fructose. The molecular formula of sucrose is C₁₂H₂₂O₁₁, which gives the atomic ratio of 12:22:11. While this is still a simple whole number ratio, the structure is far more complex than simple molecular compounds like acetylene (C₂H₂) or hydrogen (H₂). In sucrose, the atoms are arranged in a way that involves glycosidic bonds between glucose and fructose units. These bonds introduce additional complexity in the molecular structure, making the atomic ratio not as simple in terms of bonding and molecular arrangement.

In simpler molecules such as acetylene, each carbon is bonded to two hydrogens, and the molecule is linear. In benzene, although it involves resonance and an aromatic ring, the atomic ratio between carbon and hydrogen remains 1:1. On the other hand, sucrose's molecular structure includes more functional groups, and the carbon-to-hydrogen-to-oxygen ratio becomes complicated by the way the atoms are connected within the molecule.