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Changing Matter - Coggle Diagram

- - - - A chemical reaction is the process by which one or more substances are changed into one or more different substances with different properties
  - - - A permanent colour change is observed
      - However, some physical changes will give rise to colour change as well
        
        Hence, further test is needed to confirm if a chemical reaction has occurred
    - - Cloudy, foggy, solid at the bottom of a container
    - - Bubbles, smoke, odour, fumes
    - - Hot, warm, cold, explosive, glow
  - - - Reactant
        
        A substance which is present at the start of the reaction
      - Product
        
        A new substance which is produced by the reaction
      - ➝
        
        Produces, forms, yields or gives
  - - - Combustion
        
        Definition
        
        A chemical reaction when a substance burns and reacts with oxygen in air to release a large amount of heat and light
        
        A scientific term for burning
        
        Importance
        
        Burning of fuels such as petrol, natural gas and coal provides more than 90% of energy needed for transport, industries and homes
        
        Can be classified into complete and incomplete
        
        Complete Combustion
        
        A substance burns in a sufficient amount of oxygen
        
        Carbon dioxide is produced
        
        Incomplete Combustion
        
        A substance burns in an insufficient amount of oxygen
        
        Carbon monoxide and/or soot are produced
      - Thermal Decomposition
        
        Definition
        
        A single compound breaks into two or more simpler substances when it is heated
      - Combination
        
        Definition
        
        Also know as synthesis reaction
        
        A chemical reaction in which two or more substances combine to form a new compound
      - Oxidation
        
        Definition
        
        Oxygen combines with a substance to form an oxide
        
        Can take place with or without involving combustion
        
        Rusting of iron is an oxidation reaction which does not involve combustion
    - - Definition
        
        A chemical change can take place when chemical substances are exposed to light
    - - Definition
        
        Two or more substances are added together to produce new substances
    - - Definition
        
        In electrolysis, electricity is used to break down a substance into simpler substances
- - - - Molecules
      - Ions
      - Atoms
  - - - Solid
      - Liquid
      - Gas
        
        Difference between gas and vapour
        
        Gas
        
        A substance that exists naturally in gaseous state at room temperature
        
        Eg. Oxygen
        
        Vapour
        
        Used to describe the gaseous state of a substance which is normally solid or liquid at room temperature
        
        Eg. Water Vapour
  - - - Physical Change
        
        A process in which a substance undergoes changes without changing the composition and identity of the substance
      - Chemical Change
        
        A process in which a substance undergoes changes by changing the composition and identity of the substance
      - Differences between Physical Change and Chemical Change
        
        Physical Change
        
        No new substances are formed
        
        The properties of substances remain the same after a change in physical states
        
        A change could be temporary, so it can be reversed easily
        
        Chemical Change
        
        New substances are always formed
        
        The new substances have their own sets of properties which are different from the original substances
        
        A permanent change which cannot be reversed easily
- - - - Expansion and Contraction of a substance and changes in physical state require heat gain or heat loss
  - - - Average kinetic energy of particles (the motion)
      - Strength of attractive forces between the particles
  - - - Effects
        
        Increases the average kinetic energy of particles
        
        Attractive forces between particles can be overcome or weakened
      - Processes
        
        Boiling
        
        Sublimation
        
        Melting
      - Heat is taken in from the surroundings
    - - Heat is given out to the surroundings
      - Effects
        
        Decreases the average kinetic energy of particles
        
        Attractive forces between particles can be formed
      - Processes
        
        Freezing
        
        Condensation
        
        Deposition
- - - - Solid to Liquid
    - - Each pure substance melts at a fixed temperature called a melting point
    - - Temperature remains constant
        
        No change in the average kinetic energy of particles
    - - Particles in a solid gain heat energy when heated
        
        Increase in average kinetic energy of particles
      - At the melting point, the particles gain enough heat energy to break the attractive forces that hold them in their fixed positions
        
        Allows the particles to move freely in confined space and be further apart from one another
      - Solid changes into a liquid
  - - - Liquid to Gas
    - - Each pure substance boils at a fixed temperature called a boiling point
    - - Temperature remains constant
        
        No change in the average kinetic energy of particles
    - - Particles in a liquid gain heat energy when heated
        
        Increase in average kinetic energy of particles
      - At the boiling point, the particles gain enough heat energy to overcome the attractive forces that hold them in confined space
        
        Allows the particles to move freely, randomly at high speeds in all directions and far apart from one another
      - Liquid changes into a gas
  - - - Gas to Liquid
    - - Each pure substance condenses at a fixed temperature called a condensation point
        
        Same as boiling point of a pure substance
    - - Temperature remains constant
        
        No change in the average kinetic energy of particles
    - - Particles in a gas lose heat energy to the surroundings during cooling
        
        Average kinetic energy of particles decreases
        
        Particles move slower and come closer to each other
      - At the condensation point, the particles lose enough heat energy to allow the attractive forces to be formed between them to hold them together
        
        Particles can only move freely at confined spaces
      - Gas changes into a liquid
  - - - Liquid to Solid
    - - Each pure substance freezes at a fixed temperature called a freezing point
        
        Same as melting point of a pure substance
    - - Temperature remains constant
        
        No change in the average kinetic energy of particles
    - - Particles in a liquid lose heat energy to the surroundings during cooling
        
        Average kinetic energy of particles decreases
        
        Particles move slower and come closer to each other
      - At the freezing point, the particles lose enough heat energy to allow the attractive forces to be formed between them to hold them together
        
        Particles can only vibrate at their fixed positions
      - Liquid changes into a solid
- - - - Provide natural greenhouse effect on Earth
    - - Deforestation
      - Agriculture
      - Landfills and Mining
      - Burning of fossil fuels
        
        Transportation that burns fuels to power engines
        
        Industrial process such as manufacture of steel and cement
        
        Power plants that generate electricity
      - Waste management
  - - - A natural greenhouse effect
    - - This phenomenon is called enhanced greenhouse effect and this effect leads to global warming.
  - - - Rising sea levels increases the risk of coastal flooding
        
        People have to migrate to new places
    - - Some places experience longer drought while other experience frequent floods
    - - Extinction of animal species because animals lose their natural habitats
    - - Increase in widespread outbreak of disease
- - - - Unwanted substances refer to
        
        Air Pollutants
  - - - Lightning
      - Volcano Eruptions
    - - Burning of Fuels
      - Industrialisation
  - - - Source
        
        From lightning activities in the internal combustion engines
      - Effects
        
        Causes the formation of acid rain that destroys marine life and corrosion of buildings and statues
        
        Causes breathing difficulty
    - - Source
        
        Incomplete combustion of fuels containing carbon atoms
      - Effects
        
        Causes asthma attack and respiratory problems
        
        Reduces visibility in the surroundings
    - - Source
        
        Combustion of coal and fossil fuels from volcanic eruptions
      - Effects
        
        Causes breathing difficulty
        
        Causes the formation of acid rain that destroys marine life and corrosion of buildings and statues
    - - Source
        
        Incomplete combustion of fuels containing carbon atoms
      - Effects
        
        Causes asphyxiation (difficulty in breathing)
        
        Causes brain damage and death
- - - - The use of chemistry to achieve certain goals in the areas such as medicine, agriculture and manufacturing that leads to an application
  - - - Rocks
        
        Marble
        
        Construct buildings and sculptures
        
        Limestone
        
        Build statues and buildings
        
        Mud
        
        Build houses
        
        Metals
        
        Make all OYS
        
        Granite
        
        Construct buildings and houses
      - Air
        
        Oxygen
        
        In oxyacetylene for welding and tanks
        
        Carbon Dioxide
        
        In fire extinguishers and soda drinks
        
        Nitrogen
        
        Make fertilisers and nitric acid
        
        Noble Gases
        
        Helium in balloons
        
        Neon in advertising signs
        
        Argon in electric bulbs
      - Fossil Fuels
        
        Examples
        
        Petroleum (or crude oil)
        
        Coal
        
        Natural Gas
        
        Uses
        
        Fuels
        
        Plastics
        
        Cosmetics
        
        Medicine
      - Living Things
        
        Plants
        
        Wood for making furniture and building houses
        
        Animals
        
        Milk in dairy products
      - Water
        
        Seawater
        
        Table salt