science grade 9

Chapter 1: Matter

• Matter: Anything that has volume and mass.

• Volume: Takes up space.

• Mass: Made up of atoms.

Phases of Matter

1. Solid:

   • Particles are tightly packed, organized.

2. Liquid:

   • Particles are tightly packed but not organized.

3. Gas:

   • Particles are not tightly packed and not organized.

Types of Motion

1. Solid: Vibrates (shakes).

2. Liquid: Vibrates, rotates, and translates a bit.

3. Gas: Vibrates, rotates, and translates.

Chapter 2: Phase Change

• Pure Substance: Composed of one type of element, atom, compound, or molecule.

  • Examples:

    1. Diamond

    2. Glucose

    3. Table salt

Types of Substances

1. Elements: One specific type of atom from the periodic table.

   • Examples:

     1. Hydrogen

     2. Chlorine

     3. Platinum

2. Compounds: Composed of two or more different atoms connected by bonds.

   • Example: Sodium hydroxide (NaOH).

Atoms and Molecules

• Atoms: Basic building blocks of matter.

  • Examples:

    1. Hydrogen (H)

    2. Mercury (Hg)

• Molecules: Composed of multiple atoms.

Chapter 3: Mixtures

Types of Mixtures

1. Heterogeneous Mixtures: Components can be identified with the naked eye.

   • Examples:

     1. Water

     2. Oil

     3. Salad

2. Homogeneous Mixtures: Components are indistinguishable, even under a microscope.

   • Examples:

     1. Blood

     2. Milk

     3. Mayonnaise

   • Solution:

     • Example: Juices, Steel.

   • Solvent: Dissolves a solute.

     • Examples: Water, Alcohol.

   • Solute: Substance that dissolves in another substance.

Chapter 4: Properties of Pure Substances

• Characteristic Properties: Can help distinguish one substance from another.

  • Two types:

    1. Physical Properties: Changes that do not change the substance's identity (e.g., boiling, melting).

    2. Chemical Properties: Describes how a substance can change chemically (e.g., reactions with litmus paper).

Chapter 5: Energy and Change

Types of Energy

1. Thermal Energy: Energy from the vibration of atoms.

2. Chemical Energy: Stored in molecular bonds.

3. Mechanical Energy: From the speed of an object and mass.

4. Kinetic Energy: Energy of motion.

5. Potential Energy: Stored energy based on position.

6. Radiant Energy: Energy in electromagnetic waves.

Energy Transfer vs. Energy Transformation

• Energy Transfer: Movement of energy from one place to another.

  • Example: Heat traveling from the body to the air.

• Energy Transformation: Change of energy from one form to another.

  • Example: Solar energy changing to thermal energy.

Chapter 6: Waves

Types of Waves

1. Longitudinal Wave: Energy direction is left to right (e.g., sound).

2. Transverse Wave: Energy direction is up and down (e.g., light).

Properties of Sound

1. Amplitude: Height of waves; affects loudness.

2. Wavelength: Distance between two crests; affects sound properties.

3. Frequency: Number of waves in a time period; affects pitch.

Chapter 7: Light

Properties of Light

• Photons: Particles of light emitted by excited electrons.

• Amplitude: Measures brightness.

• Wavelength: Determines type of wave.

• Frequency: Measures energy and is inversely proportional to wavelength.

Radiation Types for Medical Imaging

1. X-rays: For dense objects.

2. MRI: 3D images of tissues.

3. Infrared: Color images based on temperature.

Chapter 8: Vision and Lenses

How We See

1. Light enters through the pupil and bends as it passes through the lens.

2. Light creates an inverted image on the retina.

3. Rods and cones in the retina interpret light.

Conditions Affecting Vision

1. Myopia (Nearsightedness): Difficulty seeing distant objects; corrected by concave lenses.

2. Hyperopia (Farsightedness): Difficulty seeing close objects; corrected by convex lenses.

Chapter 9: The Milky Way

• Solar System: Composed of planets revolving around a sun.

  • Planets: Mercury, Venus, Earth, Mars, Saturn, Uranus, Neptune.

• Units of Measurement:

  1. Astronomical Units (AU): Distance from Earth to the sun.

  2. Light Years: Distance light travels in one year.

Chapter 10: Conditions for Life

1. Presence of liquid water essential for cell function.

2. Essential elements: carbon and oxygen.

3. Energy source: the sun.

4. Suitable environmental conditions for stability and evolution.

5. Time: Sufficient time for life forms to evolve.