UNIT 7. MATTER

UNIT 7. MATTER AND HOW IT CHANGES 

The test will be next THURSDAY 24th March

Matter makes up all types of different material found in the Universe.

 PROPERTIES OF MATTER 

• General properties: all matter has MASS and VOLUME:
  • MASS: is the quantity of matter in an object. It is measured in grams and kilogrammes.
  • VOLUME: is the amount of space an object occupies. It is measured in cm³ and m³.
• Specific properties: are the qualities that make it different from other types of matter: colour, hardness,elasticity, density…

• DENSITY: is the relationship between mass and volume. 

^{TYPES OF MATTER}

 ^{PURE SUBSTANCES: are made of only one kind of matter. They have their own properties that make them different from the rest. Examples: gold, water, nitrogen…}

•  ^{Pure substances can be solid, liquid or gases and by cooling them down or heating them up, substances can change from one state into another.}   
• ^{MIXTURES: are made of two or more pure substances. Each pure substance is called component. In a mixture the components are not organized. The properties of mixtures can be different from the individual properties of each component.}  
  
  

^{TYPES OF MIXTURES:} 

• ^{HETEROGENOUS MIXTURES: have got visible components. Some examples are:   Pasta with tomatoe, Sand with wate}
• ^{HOMOGENOUS MIXTURES: have not got visible components.  There are also known as solutions. The substance that dissolves is the solute. The substance that dissolves it is called solvent.}  

^{The most common are:}

• ^{Water solutions}
• ^{Gas mixtures}
• ^{Alloys: are mixtures of two or more metals.}

^{Matter can change. There are two types of changes:} 

^{Physical changes: can affect the specific properties or state of a substance, but they don’t change the actual substances they are made of.}

• ^{Change of state: when substances are cooled down or heated up.}
• ^{Expansion: some materials increase in volume when they are heated up.}
• ^{Change in movement: materials can change their position when a forcacts. Ex: marble}
• ^{Deformations: materials can change shape when a force acts. Ex:rubber band}

^{Chemical changes: change the substances into new ones. These are the chemical reactions.}

• ^{COMBUSTION: burning. During combustion, combustibles(gasoline, natural gas…)combine with oxygen and burn. They are transformed into new substances and during the process, they produce light and heat.}
• ^{OXIDATION: rusting}
• ^{During oxidation substances (metal and copper) combine with oxygen and are transformed into a new substance called rust.}

^{CHEMICAL REACTION IN LVING BEINGS}

• ^{PHOTOSYNTHESIS: plants combine water and carbon dioxide using energy from the sun to produce carbohydrates.}
• ^{DIGESTION: different chemical reactions take place in order to break down food into nutrients.}
• ^{FERMENTATION: microorganisms decompose sugars and other substances.} 

 CHANGES TO MATTER