Coulomb’s Law

Learning Target I CAN qualitatively describe the relationship between charged particles using Coulomb’s Law

Criteria for Success I CAN explain what happens to the energy of attraction and repulsion between charged particles as the magnitude of the charged particles increases or decreases I CAN explain what happens to the energy of attraction or repulsion between charged particles as the distance between those charged particles increases or decreases

Coulomb’s Law Coulomb’s attraction repulsion ___________ Law is a fundamental understanding in chemistry that you will need to apply throughout this unit and future units that explains electrostatic ___________and _________, and is often referred to as the “inverse square” law. 𝐹=𝑘 𝑄 1 𝑄 2 𝑟 2 Coulomb’s attraction repulsion

Coulomb’s Law It applies to charged particles, magnets, gravitation, etc. However, we are not interested in forces; we are interested in ________ of attraction or repulsion between particles (such as atomic structure, ionization energy, lattice energy, etc.) So we perform a little calculus and we get : 𝐸=𝑘 𝑄 1 𝑄 2 𝑟 energy

Coulomb’s Law And since we are not calculating, just comparing, let’s simplify to: 𝑬 ∝ 𝑸 𝟏 𝑸 𝟐 𝒓 E = energy of attraction or repulsion between charged particles Q1 = charge of first particle Q2 = charge of second particle r = distance between charged particles

Attractive energy is negative Repulsive energy is positive Coulomb’s Law 𝑬 ∝ 𝑸 𝟏 𝑸 𝟐 𝒓 𝑬 ∝ (+)(−) (+) + - Attractive energy is negative 1 m + + 𝑬 ∝ (+)(+) (+) Repulsive energy is positive 1 m

Coulomb’s Law 2. WHEN JUSTIFYING ANSWERS ON THE FREE RESPONSE USING COULOMB’S LAW: a. The larger the _________, the larger the energy of attraction (if opposite charges) or the energy of repulsion (if like charges) charge

- Coulomb’s Law 𝑬 ∝ 𝑸 𝟏 𝑸 𝟐 𝒓 + + + - 𝑬 ∝ 𝑸 𝟏 𝑸 𝟐 𝒓 + + - Greater charge = greater energy of attraction 1 m + - Smaller charge = smaller energy of attraction 1 m

Coulomb’s Law distance 2. WHEN JUSTIFYING ANSWERS ON THE FREE RESPONSE USING COULOMB’S LAW: b. The smaller the ___________ between the particles, the larger the energy of attraction (if opposite charges) or the energy of repulsion (if like charges) distance

- Coulomb’s Law 𝑬 ∝ 𝑸 𝟏 𝑸 𝟐 𝒓 + + - 𝑬 ∝ 𝑸 𝟏 𝑸 𝟐 𝒓 + - Greater distance = smaller energy of attraction 1 m + - Smaller distance = greater energy of attraction 0.5 m

Coulomb’s Law GUIDED PRACTICE