Question

In which one of the following pairs do the two species resemble each other most closely in chemical properties: (a) \({ }_{1}^{1} \mathrm{H}\) and \({ }_{1}^{1} \mathrm{H}^{+},\) (b) \({ }_{7}^{14} \mathrm{~N}\) and \({ }_{7}^{14} \mathrm{~N}^{3-},(\mathrm{c}){ }_{6}^{12} \mathrm{C}\) and \({ }_{6}^{13} \mathrm{C} ?\) Explain.

Short answer

Pair (c) \( { }_{6}^{12} \mathrm{C} \) and \( { }_{6}^{13} \mathrm{C} \) resemble each other most closely in chemical properties.

Step-by-step solution

Understand the Concept of Isotopes and Ions

An isotope is a variation of an element that has the same number of protons, but a different number of neutrons. This means isotopes have identical chemical properties as they belong to the same element. An ion occurs when an atom gains or loses electrons, affecting its chemical properties due to a change in electric charge.

Analyze Option (a)

Option (a) presents \( { }_{1}^{1} \mathrm{H} \) and \( { }_{1}^{1} \mathrm{H}^{+} \). The latter is a hydrogen ion that has lost its electron, leaving a bare proton. This charge difference means their chemical properties will differ significantly.

Analyze Option (b)

Option (b) presents \( { }_{7}^{14} \mathrm{N} \) and \( { }_{7}^{14} \mathrm{N}^{3-} \). The \( \mathrm{N}^{3-} \) ion has gained three electrons, altering its charge and thus its chemical properties in comparison to neutral nitrogen.

Analyze Option (c)

Option (c) presents \( { }_{6}^{12} \mathrm{C} \) and \( { }_{6}^{13} \mathrm{C} \). These are isotopes of carbon, differing only in the number of neutrons. Their chemical properties are nearly identical as they both have 6 protons and remain neutral atoms.

Conclusion

Since isotopes have nearly identical chemical properties, the pair of \( { }_{6}^{12} \mathrm{C} \) and \( { }_{6}^{13} \mathrm{C} \) resemble each other the most closely in chemical properties compared to ionic relations in the other options.

Key concepts

Isotopes

Isotopes are variants of a particular chemical element. All isotopes of an element share the same number of protons, but they have different numbers of neutrons. This affects their atomic mass but not their chemical behavior.
For instance, Carbon-12 and Carbon-13 are isotopes of carbon. Both have 6 protons, which define the element as carbon, but Carbon-12 has 6 neutrons while Carbon-13 has 7 neutrons. Despite this difference, their chemical properties are almost identical because chemical behavior is largely determined by electron configuration rather than the nucleus composition with neutrons.
Understanding isotopes is crucial in fields like chemistry and nuclear physics. They help when analyzing radioactive decay and in techniques like carbon dating. Isotopes form the backbone of understanding atomic mass and mass spectrometry methods.

Ions

Ions are atoms or molecules that have gained or lost one or more electrons. This means they hold a net electrical charge. They can either be positively charged (cations) when they lose electrons, or negatively charged (anions) when they gain electrons.
For example, when a Hydrogen atom loses its single electron, it becomes a positively charged Hydrogen ion ( ext{H}^{+}). This change in electron count significantly affects its chemical properties because the ion interacts differently with other particles compared to its neutral state.
Identifying ions and understanding their behavior is a key concept in chemistry. Ions play a central role in many chemical reactions, such as those in batteries, electrolytes, and in biological systems like nerve impulses.

Neutrons

Neutrons are subatomic particles found in the nucleus of an atom, alongside protons. They have no charge and are roughly the same mass as protons.
While neutrons do not affect the chemical properties directly—instead, that is the job of electrons and protons—they do influence atomic stability and mass. The number of neutrons can vary within atoms of the same element, creating isotopes. This is critical in nuclear reactions and radioactive isotopes.
In essence, neutrons act as the glue in the atomic nucleus, stabilizing it by offsetting the repulsive forces between like-charged protons. The delicate balance of neutrons in the nucleus ensures the behavior and stability of an atom.