The Nature of Charges in an Atom
Pre-Lesson Engage
Atom's Angels — A Poem to Begin
At the heart of all matter, a nucleus sleeps,
Protons and neutrons — the secrets it keeps.
Electrons like angels circle and spin,
Its angels holding its stability — within.
📌 Your Task: Identify every keyword related to charge in this poem. Circle: Protons, Neutrons, Electrons. What does the line "Its angels holding its stability" mean to you?
Vocabulary First
Glossary of Key Terms (Part 1 of 2)
Before we dive in — let's unlock the language of atoms. Know these words and you'll own the lesson.
Proton
A positively charged particle found in the nucleus. Symbol: p⁺
Neutron
A particle with no charge found in the nucleus. Symbol: n⁰
Electron
A negatively charged particle orbiting the nucleus. Symbol: e⁻
Vocabulary First
Glossary of Key Terms (Part 2 of 2)
Let's continue building our atom vocabulary — these terms explain what happens when atoms gain or lose electrons.
Cation
An atom that loses electrons → becomes positively charged (e.g., Na⁺)
Anion
An atom that gains electrons → becomes negatively charged (e.g., Cl⁻)
Valence Electrons
Electrons in the outermost shell — they determine chemical behavior.
Vocabulary Challenge
Scrambled Letters Activity
Unscramble each word, then write its definition using context clues from the poem.
NOTICA
_ _ _ _ _ _
NAINO
_ _ _ _ _
NAVECLE LNTEERCSO
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Meet the Subatomic Particles
Every atom is built from three fundamental particles — each with a specific charge and location.
Lesson Proper — Subatomic Particles
The Three Builders of Every Atom
Proton (p⁺)
Location: Nucleus
Charge: +1
Mass: 1 amu
Count = Atomic Number (Z)
Neutron (n⁰)
Location: Nucleus
Charge: 0 (neutral)
Mass: 1 amu
Stabilizes the nucleus
Electron (e⁻)
Location: Electron cloud / shells
Charge: −1
Mass: ~0 amu
Determines reactivity
Subatomic Particle Charges
Putting Numbers to Charges
Proton
Charge: +1.602 × 10⁻¹⁹ C
Neutron
Charge: 0 C
Electron
Charge: −1.602 × 10⁻¹⁹ C
The charge of one proton and one electron are equal in magnitude but opposite in sign. This is why a neutral atom (same number of p⁺ and e⁻) has zero net charge.
Atomic Structure
Inside the Atom: Nucleus & Electron Cloud
The nucleus is incredibly dense — it contains almost all of the atom's mass in an incredibly tiny space. The surrounding electron cloud is where electrons move in energy levels called shells. Most of the atom is empty space!
Zoom Into the Core
The Nucleus — Atom's Power Center
Protons and neutrons are packed tightly in the nucleus. It is unimaginably small — about 10⁻¹⁵ meters across — yet holds nearly all the atom's mass.
Electron Shells
The Bohr Model: Electrons in Orbits (Part 1 of 2)
In the Bohr Model, electrons occupy fixed circular orbits called energy levels or shells. Each shell holds a maximum number of electrons:
Electron Shells
Shell Capacity: How Many Electrons Fit? (Part 2 of 2)
Each electron shell has a maximum number of electrons it can hold. Electrons always fill the innermost shell first before moving to the next.
Shell 1 (K)
Max: 2 e⁻
Shell 2 (L)
Max: 8 e⁻
Shell 3 (M)
Max: 8 e⁻
Hands-On Activity
Draw a Bohr Model of Sodium (Na) (Part 1 of 2)
Given: Sodium has Atomic Number Z = 11
  • 11 protons in the nucleus
  • 11 neutrons in the nucleus (for Na-23)
  • 11 electrons distributed across 3 shells
Hands-On Activity
Shell Distribution of Sodium (Part 2 of 2)
Now let's break down exactly how Sodium's 11 electrons are distributed across its 3 shells.
K Shell
2 electrons
L Shell
8 electrons
M Shell
1 valence electron ⭐
Forces Between Charges
Attraction & Repulsion: The Rules of Charge
⚡ Opposite Charges → ATTRACT
Proton (+) and Electron (−) pull toward each other.
q₁ · q₂ < 0 → Attractive Force
💥 Same Charges → REPEL
Proton (+) and Proton (+) push away from each other.
q₁ · q₂ > 0 → Repulsive Force
Force Simulation Activity
The Charge Force Diagram
The product of the charges tells us the direction of the force:
  • q₁ · q₂ > 0 (both same sign) → Repulsion — they push away
  • q₁ · q₂ < 0 (opposite signs) → Attraction — they pull together
Why the Nucleus Holds Together
The Role of Neutrons: Stability Keepers (Part 1 of 2)
If the nucleus contains only protons (all positive), they should repel each other violently and the nucleus would explode. So why doesn't it?
Enter the neutron — the peacekeeper. Neutrons contribute to the Strong Nuclear Force, which overpowers electrostatic repulsion at extremely short distances, holding protons together.
Why the Nucleus Holds Together
The Strong Nuclear Force in Action (Part 2 of 2)
The Strong Nuclear Force is one of the four fundamental forces of nature — and it's what makes stable atoms possible.
Ions: Atoms Out of Balance
Cations & Anions — When Atoms Gain or Lose Electrons
A neutral atom has equal protons and electrons. When it loses an electron, it becomes a cation (positive). When it gains an electron, it becomes an anion (negative).
Philippine Local Example
Salt on Your Dining Table — It's All About Ions!
Table Salt (NaCl) — A Perfect Ionic Bond
Sodium (Na) has 1 valence electron — it loses it easily → becomes Na⁺ (cation).
Chlorine (Cl) needs 1 more electron to complete its shell → it gains the electron → becomes Cl⁻ (anion).
The attraction between Na⁺ and Cl⁻ forms the ionic bond — and the salt you season your adobo with!
Empathize: Stability Reflection
Atoms Seek Balance — So Do Humans
Atoms with incomplete valence shells are unstable and reactive — they seek electrons to achieve balance. Humans are much the same: we seek balance in relationships, school, and life. When we are "complete," we are stable and at peace.
"Just like an atom strives for a full outer shell, we strive for wholeness — and that drive is what creates bonds."
Summary
What We've Learned Today
01
Subatomic Particles
Proton (+1), Neutron (0), Electron (−1) — each with specific charge and location in the atom.
02
Atomic Structure
Dense nucleus (p⁺ + n⁰) surrounded by an electron cloud arranged in energy shells.
03
Force of Charges
Opposite charges attract (q₁·q₂ < 0); like charges repel (q₁·q₂ > 0).
04
Ions
Atoms gain/lose electrons to form anions (−) or cations (+), driving chemical bonding.
05
Neutron's Role
Neutrons stabilize the nucleus by countering proton-proton repulsion via the Strong Nuclear Force.
Formative Assessment
Quiz Time! — 5 Questions
Write your answers on a ½ sheet of paper. Think carefully — these are not trick questions, they're brain builders!
1
Charge of −1.602 × 10⁻¹⁹ C
Which subatomic particle carries this charge?
2
Proton & Electron Force
What type of force exists between a proton and an electron?
3
Losing an Electron
If an atom loses one electron, what is the sign of its net charge?
4
Mass Location
Where is the majority of an atom's mass found?
5
True or False
Neutrons are necessary to prevent protons from repelling each other inside the nucleus.
Keep Exploring the Invisible World!
Every material around you — your phone, your desk, the air you breathe — is made of atoms governed by these exact charges. You now see the invisible architecture of matter.
Next Topic
Ionic & Covalent Bonding — how charged atoms build molecules
ICT Connection
Semiconductors in your devices rely on controlled electron behavior — atomic physics in action!
Challenge Yourself
Draw the Bohr model of Chlorine (Z=17) and identify its valence electrons at home.