Question

Answer the following questions without referring to Table 2.1: (a) What are the main subatomic particles that make up the atom? (b) What is the relative charge (in multiples of the electronic charge) of each of the particles? (c) Which of the particles is the most massive? (d) Which is the least massive?

Short answer

(a) The main subatomic particles that make up an atom are protons, neutrons, and electrons. (b) The relative charges of these particles are: protons have a charge of +1, neutrons have no charge (0), and electrons have a charge of -1 in multiples of the electronic charge. (c) The most massive particle is the neutron, with a mass of approximately \(1.68 \times 10^{-27}\) kg. (d) The least massive particle is the electron, with a mass of approximately \(9.11 \times 10^{-31}\) kg.

Step-by-step solution

(a) Identifying the main subatomic particles that make up an atom

The main subatomic particles that make up an atom are: 1. Protons 2. Neutrons 3. Electrons

(b) The relative charge of each of the particles

The relative charges of these particles are: 1. Protons: The charge of a proton is positive, and its relative charge is +1 in multiples of the electronic charge, which equals \(+1.6 \times 10^{-19}\) Coulombs. 2. Neutrons: Neutrons are neutral particles and have no charge. Their relative charge is 0. 3. Electrons: The charge of an electron is negative, and its relative charge is -1 in multiples of the electronic charge, which equals \(-1.6 \times 10^{-19}\) Coulombs.

(c) Identifying the most massive particle

The most massive of these subatomic particles is the neutron. Both protons and neutrons have roughly the same mass, but the neutron is slightly more massive. 1. Protons mass: approximately \(1.67 \times 10^{-27}\) kg 2. Neutrons mass: approximately \(1.68 \times 10^{-27}\) kg 3. Electrons mass: approximately \(9.11 \times 10^{-31}\) kg

(d) Identifying the least massive particle

The least massive of these subatomic particles is the electron, with a mass of approximately \(9.11 \times 10^{-31}\) kg, which is significantly smaller than the mass of a proton or a neutron.

Key concepts

Protons

Protons are a type of subatomic particle found within the nucleus of an atom. Protons are positively charged, carrying a charge of +1 when measured relative to the electronic charge, or more precisely, \(+1.6 \times 10^{-19}\) Coulombs. They play a crucial role in defining the element. In fact, the number of protons in the nucleus of an atom is whatwe refer to as the atomic number. This atomic number uniquely identifies each element on the periodic table. The mass of a proton is approximately \(1.67 \times 10^{-27}\) kilograms, making it one of the heavier subatomic particles found in an atom.

Neutrons

Neutrons are neutral subatomic particles, which reside in the atomic nucleus alongside protons. As their name suggests, neutrons do not have an electric charge, hence their relative charge is zero. They are slightly more massive than protons, with a mass of about \(1.68 \times 10^{-27}\) kilograms.
Neutrons play an essential role in stabilizing the atomic nucleus. Without neutrons, protons, with their like positive charges, would repel each other and the nucleus might not remain intact. The number of neutrons, along with the number of protons, determines the isotope of an element.

Electrons

Electrons are incredibly small negatively charged particles that move around the nucleus of an atom. Each electron carries a charge of -1 in relation to the electronic charge, equating to \(-1.6 \times 10^{-19}\) Coulombs. Despite their charge, electrons are negligible in terms of mass, with a weight of just \(9.11 \times 10^{-31}\) kilograms.
Their movement within an atom creates what we refer to as electron shells or clouds. These electronic configurations help define how atoms bond with each other, playing a critical role in chemical reactions and the formation of molecules.

Atomic Structure

The atomic structure refers to the layout of subatomic particles within an atom. At the center is the nucleus, consisting of protons and neutrons. This central area is surrounded by electrons, which move within regions called electron clouds or shells. These shells determine the atom's chemical properties and how it interacts with other atoms.
The balance between the number of protons (positively charged) and electrons (negatively charged) makes an atom electrically neutral. However, changes in this balance lead to ions, atoms with either a net positive or negative charge. The structure of an atom is fundamental to its identity, influencing both its physical and chemical characteristics.

Particle Charge

Particle charge is a fundamental property of subatomic particles, determining how they interact with each other.

• Protons have a positive charge, making them attract negatively charged electrons.
• Electrons possess a negative charge, which causes them to orbit the positively charged nucleus.
• Neutrons are unique in having no charge, meaning they do not contribute directly to electromagnetic interactions, but they do play a critical role in the stability of the nucleus.

The interplay of these charges helps keep atoms intact, enabling the formation of molecules and compounds.
Understanding these charge relationships is key to grasping concepts like electricity, magnetism, and chemical bonding.