Elements, compounds mixtures

What do you know already?

Our end product

• You are to research one of the following

• Water• Chlorine• Oxygen• Hydrogen• Carbon dioxide.

Uses in industry.Chlorine is used to make cleaning products such as bleach , and to provide clean drinking water, as it is poisonous to living things such as bacteria.It is also used to make Plastics such as PVC. (Poly Vinyl Chloride)

Uses in LifeIt is a poisonous gas and irritates skin even in low concentrations. However, in compounds it is vital for life often in the form of Sodium Chloride (Table Salt) Chloride is important for making stomach acid ( Hydrochloric acid) and in nerve tissues

Test for Chlorine gas.Moist litmus paper Is bleached white.

Chlorine is a molecular element with the formula Cl2.

It has the atomic number 17, and has 17 each of protons and electrons and 18 neutrons.Chlorine belongs to group 7 of the Periodic Table, which are known as the Halogens. It is a non metal.

Cl

Cl

Learning outcomesLearning outcomes

• To be able to describe elements, compounds and mixtures giving examples.

• Be able to explain the differences between elements, compounds and mixtures using the idea of atoms.

How can we sort and How can we sort and classify these? classify these? 

Elements Elements

Carbon

Helium sulphur

gold

silver

compoundcompound

Magnesium oxideCopper sulphate

water

Sodium chloride

mixturesmixtures

Dolly mixturesair

Sea water

Sulphur and iron filings

Atoms and moleculesAtoms and molecules

How is this brick like an element?

What is an atom?What is an atom?• All matter (stuff!) is made up of tiny

particles called atoms.• Atoms are the smallest particle of matter.• An element is a substance made of only one

kind of atom. All atoms of one element are exactly alike.

• Atoms of one element are different from those of another element. They have different masses and different colours.

• Atoms of one element can combine with atoms of other elements to form larger particles which we call molecules.

Megablok - atomsMegablok - atoms• Each megablok represents an atom of

an element. Different colours represent different elements.

• Sometimes we need 2 megabloks the same to make a molecule of the element.

Megablok - compoundMegablok - compound• If two or more atoms join together we

make compound.• An example is magnesium oxide. It

contains 2 different elements magnesium and oxygen.

• Sometimes we can have a mixture of different elements. They are not combined together.

Megablok - mixturesMegablok - mixtures

mixture of 3 elements

Megablok - mixturesMegablok - mixtures

• Sometimes we can have a mixture of different compounds. They are not combined together.

A mixture of 3

compounds.

Megablok - mixturesMegablok - mixtures• Sometimes we can have a mixture of

different elements and compounds. They are not combined together.

Now its your turnNow its your turn

• Write down a definition of an elementelement a compoundcompound and a mixturemixture.

• You could add a picture to help with your explanation.

• You might also add an example.

Elements, compounds and mixtures

• Elements contain only one type of atom. They are in the periodic table. E.g copper

• Compounds contain 2 or more atoms chemically combined together. E.g sodium chloride

• Mixtures contain a mixture of elements or elements and compounds not combined together. E.g air

Now try theseNow try these

• On your desk there are diagrams of atoms and molecules.

• You need to decide if they are representing elements, compounds or mixtures and also explain why.

• Draw them outDraw them out in your book and explain explain your findingsyour findings in as much detaildetail as you can.

Look at these diagrams of atoms and molecules

Which ones are elements, which ones mixtures and which ones compounds?

Can you be more detailed and say if they are mixtures of elements or mixtures of compounds?

Spot the difference…Spot the difference…instructionsinstructions

• On your desk you have 12 statements.

• With your partner decide if the statement represents an element, a element, a compound, a mixture or a variety of compound, a mixture or a variety of these.these.

• Give an reasonreason why you have made your answer using your science understanding.

Spot the differenceSpot the difference 1. Contain chemicals. 2. Have a definite composition. 3. Are made up of atoms. 4. Include air, soil and sea water. 5. Contain only one type of atom. 6. Can be represented by a chemical formula. 7. Include oxygen, iron, sulphur and sodium . 8. Contain more than one type of atom.9. Contain different substances that are not chemically combined.10. Can be solids, liquids or gases.11. Include water, salt, sugar and carbon dioxide. 12. Contain molecules.

Science HomeworkScience Homework

• Open your planner and write in Open your planner and write in your science homework.your science homework.

• Complete the sheet on elements, Complete the sheet on elements, compounds and mixtures for compounds and mixtures for next science lesson (DATE)next science lesson (DATE)