Question

Match column I and II column I \(\frac{\text { column I }}{\text { fnucleus }}\) (a) size of (b) number of Proton in a nucleus column II (p) Z (q) \(10^{-15} \mathrm{~m}\) (r) \((\mathrm{A}-\mathrm{Z})\) (s) \(10^{-10} \mathrm{~m}\) 0 (c) size of Atom (d) Number of neutrons in a nucleus (A) \(\mathrm{a} \rightarrow \mathrm{r}, \mathrm{b} \rightarrow \mathrm{s}, \mathrm{c} \rightarrow \mathrm{q}, \mathrm{d} \rightarrow \mathrm{p}\) (B) \(\mathrm{a} \rightarrow \mathrm{q}, \mathrm{b} \rightarrow \mathrm{p}, \mathrm{c} \rightarrow \mathrm{s}, \mathrm{d} \rightarrow \mathrm{r}\) (C) \(\mathrm{a} \rightarrow \mathrm{s}, \mathrm{b} \rightarrow \mathrm{r}, \mathrm{c} \rightarrow \mathrm{q}, \mathrm{d} \rightarrow \mathrm{p}\) (D) \(\mathrm{b} \rightarrow \mathrm{s}, \mathrm{c} \rightarrow \mathrm{p}, \mathrm{c} \rightarrow \mathrm{q}, \mathrm{d} \rightarrow \mathrm{r}\)

Short answer

The correct matching pairs for the given question are (B) a → q, b → p, c → s, d → r.

Step-by-step solution

Analyzing options in Column I

First, let's analyze each option in column I to understand what they are referring to. (a) size of - This option is incomplete. We need to look for sizes of nucleus and atom. (b) number of Proton in a nucleus - Refers to the number of protons in a nucleus which is denoted by 'Z'. (c) size of Atom - Refers to the approximate diameter of an atom. (d) Number of neutrons in a nucleus - Refers to the number of neutrons in a nucleus, which can be calculated by subtracting the number of protons (Z) from the mass number (A): (A-Z).

Matching column I options with correct column II options

Now that we understand the options in column I, let's find the appropriate matches in column II. (a) size of - Incomplete, we should look for both nucleus and atom sizes. (b) number of Proton in a nucleus - Refers to 'Z', so the correct match is (p). (c) size of Atom - The approximate diameter of an atom is about \(10^{-10} \mathrm{~m}\), so the correct match is (s). (d) Number of neutrons in a nucleus - Can be calculated using (A-Z), so the correct match is (r). Now that we have paired options from column I to column II, let's see which answer choice corresponds to our matched pairs:

Checking the answer choices

Comparing our matched pairs with the answer choices, we find that our pairs match with choice (B): (B) a → q, b → p, c → s, d → r So, the correct answer is (B).

Key concepts

Atomic Structure

Every atom is essentially made up of three fundamental components: electrons, protons, and neutrons. These pronounce the structure and characteristics of an atom. Understanding atomic structure is key to delving deeper into nuclear physics and its various phenomena.

• **Electrons**: Negatively charged particles that orbit the nucleus in various energy levels or shells. Their movement and arrangement dictate the atom's chemistry.
• **Protons**: Positively charged particles located in the nucleus. They determine the atomic number and identity of the element.
• **Neutrons**: Neutral particles present in the nucleus alongside protons. They have no charge, but contribute to the mass of the atom.

The nucleus is the heart of the atom where protons and neutrons are densely packed together, accounting for most of the atom's mass. The electron cloud surrounding the nucleus creates the atomic size, usually quantified based on the distance between the nucleus and the outermost electrons.

Protons in a Nucleus

Protons are integral to defining what element an atom represents. Each element in the periodic table is characterized by its atomic number, which corresponds to the number of protons present in its nucleus. This atomic number, usually denoted as 'Z', is unique to each element.

For instance, a nucleus with 1 proton is hydrogen, whereas a nucleus with 2 protons is helium. The protons not only determine the element but also influence chemical properties by balancing the negative charge of electrons, making the atom electrically neutral in most cases. Recognizing the count of protons helps in various nuclear calculations and predictions about chemical bonding and stability.

Size of Atom

The size of an atom is primarily gauged by its atomic radius, which is the distance from the nucleus to the outermost electron shell. In general, the size of an atom is on the order of magnitude of about \(10^{-10} \text{ m}\). This extremely small scale challenges our conventional perceptions of "size".

• Typically, the atomic size is determined by electron distribution, which varies across elements.
• Noble gases tend to have larger sizes due to complete electron shells, whereas atoms losing electrons become smaller.

Understanding atom size is crucial in fields like chemistry and materials science, where reactions and crystal structures depend heavily on spatial arrangement of atoms.

Neutrons in a Nucleus

Neutrons play a key role in contributing to the mass and stability of the nucleus. Interestingly, they don't affect the chemical properties of an atom, unlike protons and electrons. Instead, they help in moderating the repulsive forces between protons due to their charge neutrality.

The number of neutrons can be deduced using the equation: \( \text{Number of Neutrons} = A - Z \), where 'A' represents the mass number (sum of protons and neutrons), and 'Z' refers to the atomic number or number of protons.

• In isotopes, neutron count varies while the proton number remains constant, producing different physical properties.
• The balance between protons and neutrons governs the stability of the nucleus, with optimal ratios necessary for nuclear stability.

In nuclear reactions and processes, the role of neutrons is pivotal, showcasing how intricate the forces at subatomic levels truly are.