Chemical Energy

Learning Intention: Students will understand the relevance of specific chemical reactions to everyday life and be able to describe the usefulness of those reactions to society.

Success criteria: Students will produce a poster, slideshow or video that investigates and describes a specific chemical reaction and it’s usefulness in our lives.

Your task is to research one of the following materials and how they can react to produce useful results – a release of heat, a new product or a portable source of energy for example. Find out how these materials are extracted or produced, the useful reaction that occurs and how this reaction benefits society. Are their any disadvantages of this reaction? (eg. greenhouse gases produced, finite resources being used or toxic by-products?

  1. Fossil Fuels (oil, coal or gas – choose one) – combustion
  2. Dynamite explosions
  3. Electrolysis to allow silver plating, copper plating etc
  4. Batteries – (car battery, torch battery, lithium rechargable battery etc)
  5. Biofuels – ethanol for sugar cane or corn, methane from effluent or garbage, biodeisel from abbatoir waste, algae or waste oils)

This project is due next Monday, 14th May and will be assessed for your end of term report.

 

 

Year 8 Chemical Reactions

Rusty tractor engine

This a rusty tractor engine, captured at Jurien Bay, WA.

Over the next few weeks we will be doing many different experiments, including turning grass into paper. After you have finished this unit of work, you should be able to answer the following questions:

  1. What are the two main differences between physical change and chemical reactions?
  2. What are four signs that new products are formed during a chemical reaction?
  3. Name four ways you can increase the rate of a reaction.

Freezing, melting, evaporation and condensation are all physical changes of state in which molecules of a substance gain or lose kinetic energy. Many common changes that occur around us are actually chemical reactions – when iron rusts, apples go brown, silver tarnishes or copper develops a green tinge, oxidation is occurring. Combustion (burning) is also a form of oxidation. In a chemical reaction new products are formed and this may result in a colour change, a precipitate being formed, the release of gases or energy in the form of light or sound. The following resources may help you to learn about chemical reactions:

Check out our Voicethread about Chemical reactions:

 

What would you like to learn about in Science next? Please go to the Wallwisher and leave a post-it note letting me know what you are interested in doing in Year 8 Science.

The Carbon Cycle – “My Life as a Carbon Atom”

photosynthesis comic

Your task is to write a short story titled “My Life as a Carbon Atom” to demonstrate your understanding of the following processes:

  • Photosynthesis – green plants use sunlight to convert carbon dioxide and water into carbohydrate (glucose) that is used by all other living organisms as the source of food.
  • Respiration – all living organisms (with the exception of a few bacteria) use oxygen to convert carbohydrates into energy, releasing carbon dioxide and water into the atmosphere.
  • Decomposition – Bacteria and fungi break down organic matter (leaves, wood, dead animals etc) into carbon dioxide and water during respiration.
  • Fossil Fuel formation – Oil, coal and gas are formed after millions of years under extreme pressure and high temperatures, from once living organisms such as trees and microscopic algae.
  • Combustion – wood, gas, oil, coal and other carbon-containing compounds can be burnt with oxygen to produce carbon dioxide.

Your story should be at least 500 words long (100 words for each process) and be written from the perspective of a carbon atom. Take your inspiration from the videos (Clickview “Carbon Cycle” and the DVD “Crude”) and use the carbon cycle diagram on page 47 of Science Quest 2.

You can also use “Comic Life”, “Vociethread’, “Photostory”, “Kerpoof” or “Storybird” to illustrate your story.

Due Tuesday 15th March

fossil fuels comic