*Elements Compounds and Mixtures

*Element, mixture or compound?

*Is it an element, compound or mixture?Scientists like to classify things.One way that scientists classify matter is by its composition.Ultimately, all matter can be classified as mixtures, elements and compounds.

*Why isnt it a good idea to classify matter by its state?Because one kind of substance can exist in more than one state such as H20. And matter changes phases rather easily.Remember Topic 3 The World of Chemistry

*What is an element?An element is a pure substance that cannot be broken down into simpler substances.A pure substance is a substance in which there is only one type of particle.An element is a chemical that contains only one type of atom. Pure gold is an element because it contains gold atoms only.

*All the elements are found on the

*What are atoms?All chemicals are examples of matter.All matter is made up of extremely small particles called atoms.Learn more about atoms in LO 4

*What are compounds?A compound is a substance that contains different elements (different atom types) chemically joined togetherHere are some examples:

*CompoundsA compound is a pure substance composed of two or more elements that are chemically joined together.Compounds are new substances produced by chemical reactions. To be chemically combined, the elements in the compound need to have reacted with one another.Most elements are not found alone in nature, but rather combined with other elements. Most substances you encounter are compounds!A compound has fixed proportions of the different elements. Eg. water

*Glucose is a compoundContaining the elements:CarbonHydrogenoxygenC6H12O6

*What are molecules?Molecules are groups of atoms joined together.

The compound water is a molecule containing 2 hydrogen atoms joined to an oxygen atom.The element oxygen forms molecules of oxygen gas = O2

*MixturesA mixture is a combination of two or more substances that are not chemically combined.

When you mix up chemicals and no new substance is produced then a mixture is formed.Substances in a mixture retain their identity, they do not change into something else.Mixtures can be physically separated through physical change. Eg: picking the pecans out of pecan pie, boiling salt water to evaporate the water and leave the salt.

*AirAir is a mixturewhich can be separated see LO 879%79%21%18%

*Classification of Matter Overview

*Test yourselfIs it an element, compound or mixture?

*(Gas)One ElementThe Same Element(Solid)

*This one likes to go round in pairs as a gas (molecules)Another elementA mixture of two elements

*This is not a mixture, it is a COMPOUND of two different elementsThis is just a mixture of two elements

*Element, Compound or Mixture ?

*Element, Compound or Mixture ?Element

*Element, Compound or Mixture ?

*Element, Compound or Mixture ?Element

*Element, Compound or Mixture ?

*Element, Compound or Mixture ?Mixture

*Element, Compound or Mixture ?

*Element, Compound or Mixture ?Compound

*Element, Compound or Mixture ?

*Element, Compound or Mixture ?Compound

*Element, Compound or Mixture ?

*Element, Compound or Mixture ?A mixture of a compound and an element

*What do we call these things?6 Atoms which happen to be of 3 different elements

*What do we call these things?A MoleculeYes, it also happens to be 2 atoms joined together but we dont call it 2 atoms joined together we say it is one molecule

*What do we call these things?A Molecule of a compound2 molecules of a compound

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