Heat

• The heat absorbed by the ice cubes makes them melt
• Particle Theory of Matter

  Matter consists of many very small particles that are in constant motion and are held together by attractive forces
• Heat


  • It is the thermal energy that flows between bodies or regions due to temperature difference
  • It is considered energy in transit
• When your hand touches an ice cube or any object with a lower temperature than your hand, you begin to feel cold, as your body heat is transferred to the colder object
• Conduction

  1. It is the process by which heat occurs through a medium from one point to another

  2. When heated, the molecules gain energy and move faster. As they move through the limited space, they tend to collide and their energy is transferred to their neighboring molecules more quickly
• Objectives

  1. Explain the difference between heat and temperature

  2. Describe the conditions necessary for heat transfer to occur

  3. Identify the different modes of heat transfer

  4. Relate how heat transfer is involved in one’s daily activities
• Convection


  1. It is the process wherein thermal energy is transmitted from one material to another by the movement of heated particles of a fluid like liquid or gas

  2. The amount of thermal energy is dependent on the amount of heated matter transferred
• Thermal Energy


  The speed by which atoms and molecules move depends largely on the energy they contain. This energy is called thermal energy
• Sea Breeze and Land Breeze

  • Land breeze refers to the breeze or wind blowing from the land towards the sea. It usually occurs during the night or early morning when the land air is cooler than the sea air
  • Sea breeze refers to the breeze or wind blowing from the sea towards the land
• Hotter objects tend to give off heat

  Heat flows from hotter bodies or objects to colder ones. If there is no temperature difference, there will be no heat transfer
• States of Matter

  • Solid
  • Liquid
  • Gas
• Temperature

  • It measures the average amount of kinetic energy in an object
  • For example: Hot water has molecules that move faster than molecules of cold water
• References: Ferriols-Pavico, et al. Exploring Life Through Science Grade 7. Quezon City, Philippines: Phoenix Publishing House, Inc. 2020. Papa, Eduard, et al. Practical Science 7. Makati City, Philippines, Diwa Learning Systems Inc., 2018
• Convection is not the transfer of heat by direct contact
• Radiation

  • Microwave oven cooking food by water molecules inside absorbing microwave radiation and heating up, consequently heating the surrounding food
• Boiling water

  Temperature of molecules within the water increases, they move at a rapid rate upwards, hot water molecules become less dense and rise above denser cooler molecules
• Homework: Read about heat and the environment, advantages and disadvantages of heat transfer in the environment, and the greenhouse effect and its causes
• Temperature is the measure of the average kinetic energy of the particles of a substance
• Sea breeze

  Breeze or wind blowing from the sea towards the land, occurs during the summer days
• Radiation

  Transfer of thermal energy by electromagnetic (EM) waves, can take place in a vacuum unlike conduction and convection
• Land breeze

  Breeze or wind blowing from the land towards the sea, occurs during the night or early morning when the land air is cooler than the sea air
• Convection

  • Energy radiating from the sun to Earth via electromagnetic waves
• For those who joined outdoor sports, protecting oneself from the heat of the sun includes applying sunblock or sunscreen and drinking water to rehydrate
• Heat flows from a body at higher temperature to one at a lower temperature
• Conduction


  Heat moves from one object to another object through direct touch (occurs through a medium)
• States of matter

  • Solids
  • Liquids
  • Gas
• Temperature


  It measures the average amount of kinetic energy in an object
• Radiation


  Energy that comes from a source and travels through space at the speed of light (this can also be called electromagnetic waves and can take place in a vacuum)
• English Physicist Isaac Newton theorized that light is made up of tiny particles
• Land Breeze and Sea Breeze

  1. Land breeze - The breeze or wind blowing from the land towards the sea, usually occurs during the night or early in the morning when the land air is cooler than sea air

  2. Sea breeze - The breeze or wind blowing from the sea towards the ocean, usually occurs during the summer days
• Dutch physicist Christiaan Huygens proposed that light was a wave
• The Earth’s atmosphere shields us from extreme temperatures
• Greenhouse gases

  • Methane
  • Carbon dioxide
  • Nitrous oxide
  • Fluorinated gases
• German physicist Max Planck theorized that light was emitted in packets of energy called quanta
• James Maxwell proved that light is a transverse wave that is partly magnet and electrical in nature
• Atomic structure


  The electron theory explains the existence of charges in an atom
• Properties of Light

  Rectilinear propagation of light - A property of light that shows how light travels in a straight line through a homogenous and transparent medium
• Electricity

  Amber - The fossil resin that the Greeks used to study static electricity was amber (when amber is rubbed vigorously with a piece of cloth, it can attract nearby objects
• • Conservation of electric Charge - When two different objects are rubbed against each other the electrons transfer from one object to the other
  • No electron is destroyed nor created during the process
  • The sum of positive and negative charges during the process of rubbing is ZERO
• Visible light (ROYGBIV) lies on the electromagnetic spectrum and will consist of colors depending on which spectrum it lies in