Lesson Notes By Weeks and Term v4 - SHS 2
NUCLEAR PHYSICS
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
NUCLEAR PHYSICS
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Physics
Class: SHS 2
Term: 2nd Term
Week: 19
Grade code: 2.4.1.LI.1
Strand code: 4
Sub-strand code: 2
Content standard code: 2.4.1.CS.1
Indicator code: 2.4.1.LI.1
Theme: ATOMIC AND NUCLEAR PHYSICS
Subtheme: NUCLEAR PHYSICS
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
This lesson introduces the heart of the atom: the nucleus. We will move beyond the electron shells and delve into the tiny, dense core that defines an element and holds immense energy. Understanding the nucleus is fundamental to comprehending everything from how the sun produces energy to how hospitals in Ghana use radiation to treat cancer (radiotherapy) and how our nation is exploring nuclear power for electricity. We will explore the particles that make up the nucleus and uncover the secret to the immense energy locked within it, a concept explained by Einstein's famous equation, E=mc².
2.1 The Composition of the Nucleus
The centre of every atom is the nucleus. It is incredibly small and dense, containing almost all the atom's mass. The nucleus is made of two types of particles, collectively called nucleons. Protons: Positively charged particles. The number of protons determines the element. For example, any atom with 6 protons is Carbon. Any atom with 92 protons is Uranium. The number of protons is called the Atomic Number (Z). Neutrons: Neutral particles (no charge). They have a mass very similar to that of a proton. Neutrons help to stabilise the nucleus by providing attractive nuclear forces to counteract the electrostatic repulsion between the positively charged protons.
The total number of protons and neutrons in a nucleus is called the Mass Number (A). Therefore: Mass Number (A) = Number of Protons (Z) + Number of Neutrons (N) or N = A - Z 2.2 Nuclide Notation We represent a specific nucleus (called a nuclide) with the following notation: `A_Z X` Where: X is the chemical symbol of the element (e.g., C for Carbon, U for Uranium). A is the mass number (total number of protons + neutrons). Z is the atomic number (number of protons).
Example: Consider the most common form of Carbon, Carbon-12. Its notation is `12_6 C`. From this, we know: The element is Carbon (C). Atomic Number (Z) = 6. This means there are 6 protons. Mass Number (A) = 12. Number of Neutrons (N) = A - Z = 12 - 6 = 6 neutrons.