MATTER CHANGES

MATTER CHANGES

1. Mixtures

   • What is a mixture?
     • A mixture is a physical combination of two or more substances
     • Types of mixtures
       • Heterogenous
         • We can see the various substances because they are not combinad evenly, we can alto separate them.
       • Homogenous
         • We can not see the diffevento substances because they are more evenly combined
   • Ways of separating mixtures
     • Magnetic separation
       • We can use it to separate magnetic substances like iron from non-magnetic ones su hijo as paper and plastic
     • Decantation
       • We can use it to separate mixtures of liquids and solids and liquids with different densities
     • Filtration
       • We can use it to separate small particles from liquids or gases. A filter stops the particles in but lets the liquid or gas pass through
     • Evaporation
       • A solution is a special type of homogenous mixture made up of a solid dissolved into a liquid. When we heat the liquid, it becomes a vapour and leaves the solid behind
     • Distillation
       • We can use distillation to separate liquids with different boiling points ( the temperature. at wich the liquid starts to evaporate) . One liquid evaporates first ,and them, we cool it to liquid form.
     • Sieiving
       • We can use it to separate solids of different sizes.

2. Chemical reactions

   • What is a chemical reaction?
     • When a chemical reaction occurs, it changes the properties of a substance and produces something different. they are caused by agents. Matter 1+ Agent = Matter 2
   • Types
     • Combustion
       • It produces energy in the form of light and heat. It occurs when oxygen in the air reacts wih a fuel such as wood, petrol or natural gas. When fuels burn, some waste products era produced. Fuel + O² = Energy ( light and heat) and waste products.
         • When wood burns, it produces smoke and ash. It also produces waste gases such as carbon dioxide. Wood + O² = light and heat (energy) and smoke, ash, CO² and other gases.
         • When petrol burns, it produces carbon dioxide and other gases. It also releases solid particles into the air. Petrol + O² = light, heat, mechanical energy, CO², other gases and solid particles.
         • When natural gas burns, it produces carbon dioxide and other waste gases, but it is claner than wood or petrol. Natural gas + O² = light and heat (energy),CO² and other waste gases.
     • Oxidation
       • Some metals reat when they are exposed to air. Iron reacts with oxygen in the air and changes to a brown substance called rust. This is called oxidation. Some food also oxidise. Some metals ( iron) + O² = rust.
     • Fermentation
       • It is caused by fungi and bacteria. They break down organic materials and produce new substances. Yeast is a fugus that ferments bread and produces carbon dioxide wich makes the dough rise. Other foods are fermented by bacteria. Cheese, yoghurt, pickles, olives and chorizo sre fermented by bacteria thet produces lactic acid. This process helps to preserve the food. Organic substances + fungi or bacteria.