Term 2 Week 5 2016

Homework

• Ex 5A, P. 151-155, Models of the Atom

Parts of the Atom

Isotopes

Isotopes are versions of an atom or an element that have the same number of protons, but different numbers of neutrons

Radioactive Decay

Alpha, Beta & Gamma Radiation

• Alpha particles are emitted by a larger nucleus that has too many Protons
• Beta particles are emitted by a nucleus that has too many Neutrons
• Gamma photons are emitted by a nucleus that has too much Energy (is in an exited state)

• PhET Alpha Decay app can be found here
• PhET Beta Decay app can be found here

Alpha Decay

Beta Decay

Radiation

Types of Radiation

Half-Life

Half-Life Explanation

Half-Life Calculations

Half-Life Formula

A = Ao(½)n

A: Amount of radioactive substance now present

Ao: Amount of radioactive substance originally present

n: Number of Half-Lives that have past

If you can understand the maths for using the formula above, you will be able to pinpoint your answers instead of estimating them using a graph.

You will need to be able to use the 3rd Log Law to solve for half lives.

Term 2 Week 4 2016

Homework

Complete Ex 3B, p.47-52 Light Refraction

Models of the Atom

Thomson's Plum Pudding Model

Rutherford's Gold Foil Experiment

Term 2 Week 3 2016

Homework

• Ex 3G, p.76-79, Two Point Source Interference
• Ex 3H, p.81-83, Wave Reflection
• Ex 3I, p. 85-87, Wave refraction
• Ex 3B, p.47-52, Light Refration

Refraction of Light

v1/v2 = 𝛌1/𝛌2 = sin(𝜭1)/sin(𝜭2) = n2/n1 ← Wave Refraction

n1sin(𝜭1) = n2sin(𝜭2) ← Snell’s Law (light only)

Critical Angle

This is when the refracted angle equals 90o

Therefore sin(𝜭c) = n2/n1

PhET Simulation on Light Refraction

Use this simulation when answering questions to help your understanding

Term 2 Week 2 - 2016

Homework

• Ex 3G, p. 76-79 Two Point Source Interference
• Ex 3H, p. 81-83 Reflection and Superposition on a String
• Ex 3I, p. 85-87 Refraction and Superposition on a String

Diffraction

Interference and Superposition

Two Point Source Interference

Waves on a String

Cymatics

Term 2 Week 1 - 2016

Waves

Homework;

• Ex 3D, p. 66-67 Wave Properties
• Ex 3E, p. 69-70 Waves & Wavefronts
• Ex 3F, p. 73-75 Interference & Superposition

Basic Wave Properties

Longitudinal Waves

In Longitudinal waves the particle displacement in the medium is parallel to the direction of wave propagation.
e.g. Sound Waves are Longitudinal Waves

Transverse Waves

In transverse waves the particle displacement in the medium is perpendicular to the direction of wave propagation.
e.g. Light Waves and all Electromagnetc (EM) Waves are Transverse Waves

Wavelength