Problem 10 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

The periodic table consists of 18 groups. An isotope of copper, on bombardment with protons, undergoes a nuclear reaction yielding element \(X\) as shown below. To which group, element \(X\) belongs in the periodic table? [2012] \({ }_{29}^{63} \mathrm{Cu}+{ }_{1}^{1} \mathrm{H} \rightarrow 6_{0}^{1} n+{ }_{2}^{4} \alpha+2{ }_{1}^{1} \mathrm{H}+X\)

Step-by-Step Solution

Answer

Element X is Nickel, which belongs to group 10.

Step 1: Analyze the given reaction

The nuclear reaction given is \( \{{}_{29}^{63}\mathrm{Cu} + \; {}_{1}^{1}\mathrm{H} \rightarrow \; {}_{6}^{0} n + \; {}_{2}^{4}\alpha + \; 2{ }_{1}^{1} \mathrm{H} + X\} \). We must determine the element \( X \). Start by understanding that the copper isotope \( {}_{29}^{63}\mathrm{Cu} \) collides with a proton \( {}_{1}^{1}\mathrm{H} \).

Step 2: Calculate the product of the reaction

In the reaction, the proton \( {}_{1}^{1}\mathrm{H} \) causes the copper isotope to undergo a nuclear transformation. The total change in atomic number is \(-2\) (because of \( {}_{2}^{4}\alpha \)), and the total change in mass number is \(-4\) (because of \( {}_{2}^{4}\alpha \)). So, atomic number \( Z_X = (29 + 1 - 2) = 28 \) and mass number \( A_X = (63 + 1 - 4) = 60 \).

Step 3: Identify element X

Element \( X \) has atomic number 28 and mass number 60. From the periodic table, the element with atomic number 28 is Nickel (Ni). Hence, \( X \) is \( {}_{28}^{60}\mathrm{Ni} \).

Step 4: Determine the group of element X

Nickel (Ni) is located in group 10 of the periodic table. Elements in group 10 are characterized by the presence of transition metals. Therefore, element \( X \), which is Nickel, belongs to group 10.

Key Concepts

Nuclear Reactions

Nuclear reactions are processes that involve a change in an atom's nucleus, leading to the transformation of elements. They differ from chemical reactions, which only involve the electrons surrounding the nucleus.
These reactions typically release a significant amount of energy, much more than chemical reactions. This energy is due to the conversion of mass into energy, following Albert Einstein's famous equation, \(E = mc^2\), where \(E\) is energy, \(m\) is mass, and \(c\) is the speed of light.

• In nuclear reactions, particles like protons, neutrons, or even entire nuclei collide and interact.
• They can result in the emission or absorption of particles, including neutrons, protons, or alpha particles, as seen in the example reaction.

In the given exercise, a copper isotope undergoes a nuclear reaction when bombarded with protons. This interaction results in a series of nuclear transformations and the emission of different particles, finally producing element X (Nickel). Here, energy is released, and new isotopes form, showcasing nuclear power and reactivity.

Isotopes

Isotopes are different forms of the same chemical element, each having a different number of neutrons.
While isotopes of an element share the same atomic number (number of protons), they differ in mass numbers due to varying neutron counts.

• An element can have several isotopes, some of which may be stable, while others are radioactive, known as radioisotopes.
• Physical and chemical behaviors can vary slightly between isotopes, although many properties remain the same.

For instance, in the example, \( {}_{29}^{63} ext{Cu} \)represents an isotope of copper with 34 neutrons. By understanding isotopes’ nature, it becomes clear how a specific copper isotope can undergo different nuclear reactions than others, depending on its neutron-to-proton ratio. Identifying isotopes is crucial, especially in nuclear reactions, to predict outcomes and product elements.

Transition Metals

Transition metals are a significant group of elements located in the central block of the periodic table, specifically between groups 3 and 12. They are characterized by their ability to form variable oxidation states and to create colorful compounds.

• Transition metals include well-known elements like iron, copper, and nickel.
• They are typically defined by the presence of electrons in d-orbitals.

Nickel, the element identified in the given nuclear reaction, falls into this category and belongs to group 10 on the periodic table. Transition metals are known for their:

• High melting and boiling points
• Good conductivity of electricity
• Strong structural properties, often using them in construction and technology

Understanding where elements like nickel fit on the periodic table helps reveal their chemical and practical properties, explaining why nickel serves as a transition metal and its applications, from catalysis to coinage.