Core Chemistry C1 PLACE lesson 1

1. Core ChemistryC1PLACE lesson 1 The Periodic Table Atomic structure Elements and compounds

2. Atomic structure-specification • a) All substances are made of atoms. A substance that is made of only one sort of atom is called an element. • There are about 100 different elements. Elements are shown in the periodic table. The groups contain elements with similar properties. • b) Atoms of each element are represented by a chemical symbol, e.g. O represents an atom of oxygen, and Na represents an atom of sodium. • c) Atoms have a small central nucleus, which is made up of protons and neutrons and around which there are electrons. • d) The relative electrical charges are as shown: • Proton +1 • Neutron 0 • Electron –1 • e) In an atom, the number of electrons is equal to the number of protons in the nucleus. Atoms have no overall electrical charge. • f) All atoms of a particular element have the same number of protons. Atoms of different elements have different numbers of protons. • g) The number of protons in an atom of an element is its atomic number. The sum of the protons and neutrons in an atom is its mass number. • h) Electrons occupy particular energy levels. Each electron in an atom is at a particular energy level (in a particular shell). The electrons in an atom occupy the lowest available energy levels (innermost available shells). • Represent the electronic structure of the first 20 elements of the periodic table in the following forms: x x sodium 2,8,1 x x x x x x x x x x

3. Particles • Single particles or atoms are far too small to be seen. • We have to work out what they are like by using our imagination. • Diagrams help us to picture what they are like. • The simplest idea is that they are like solid balls.

4. Particles • This is a tiny piece of a solid. • The particles stick close together in a lump. • They are held in place by forces of attraction called bonds.

5. Particles • The particles in a liquid are more spread out. • They still attract so stick together in the bottom of the container. • If they get hotter, they move about faster.

6. Particles • In a gas the particles are far apart and fill the container. • As the gas gets hotter, they move about faster. • They cause pressure when they hit the sides.

7. Particles • When a solid melts the bonds between the particles break and it turns into a liquid. • The melting point is the temperature when it does this.

8. Particles • When a liquid is heated the particles move faster. • Even at low temperature some particles escape. • They turn into a vapour.

9. Particles • At the boiling point all particles are moving fast enough to escape. • It turns to gas.

10. Particles • Elements are substances that are pure. • They are only made of one type of atom. • They can be solids, liquids or gases.

11. Particles Elements, compounds and mixtures

12. Particles • Mixtures of different things can be separated by simple physical means. • This is a mixture of different gases. worksheet

13. The Periodic Table of elements I 0 Group number III IV VI VII II V Period number You will get one of these in any chemistry exam from now on. You need to know how to use it. It is a look-up and use the information sort of thing! There are 92 elements found in nature Over 20 man-made elements. A database to show relationships among these elements http://www.bbc.co.uk/learningzone/clips/groups-and-periods-in-the-periodic-table/10623.html

14. Elements • Elements are made from the same sort of atom • H (hydrogen), Na (sodium), F (fluorine) • Name these elements • Ne, S, Cu, O, Mg, Mn, K, Fe • Name and find the atomic number and relative atomic masses for the following atoms showing: • H, F, Na, Cl, Br, U, Os, Fe, K, Ar, and Al Annotate your Periodic Tables with the following information: Group names Metals and non-metals Liquids and gases

15. Parts of an atom • What are the three types of particle inside an atom? • What is the charge and the mass of each particle of an atom • Where are the 3 particles to be found in the atom?

16. What are the 3 major parts of an atom?

17. What are the 3 major parts of an atom? • Proton • Neutron • Electron Draw a diagram showing the location of each part of the atom.

18. Draw a diagram showing the location of each part of the atom.

19. Draw a diagram showing the charges of each part of the atom.

20. Draw a Diagram of an Atom

21. Describe Proton • Protons are positively charged particles found in the atomic nucleus • Protons were discovered by Ernest Rutherford

22. Describe Neutron • Neutrons are uncharged particles found in the atomic nucleus • Neutrons were discovered by James Chadwick in 1932

23. Describe Electron • Electrons are negatively charged particles that surround the atom's nucleus. • Electrons were discovered by J. J. Thomson in 1897. • Electrons determine properties of the atom. • Chemical reactions involve sharing or exchanging electrons between elements.

24. Describe Nucleus • The nucleus is the central part of an atom. It is composed of protons and neutrons. • The nucleus contains most of an atom's mass. • It was discovered by Ernest Rutherford in 1911.

25. Sub-atomic particles • In the nucleus • Protons • Charge +1 • Mass 1 • Neutrons • Charge 0 • Mass 1 • Outside the nucleus • Electrons • Charge -1 • Mass 0.0005 (or 1/1840 (very small compared to proton & neutron))

26. Building a nucleus

27. Atomic structure-summary Number of protons and neutrons Mass Number Relative Atomic Mass X • Matter (space & mass) • Element • One type of atom • Atomic number (# of protons) • Mass number (# of protons + # of neutrons) Atomic Number Number of protons Diagram of the atomic structure of the lithium atom Key: Electron Neutron Proton  Li    Represent electrons as dots or crosses X

28. How are electrons arranged?

29. Energy level rules The Period Number tells you which energy level is being filled. The Group Number tells you how many electrons there are in the outermost energy level. The most stable elements have a the maximum number of electrons in their outer energy level. nucleus You need to know or be able to work out the electronic structure of the first 20 elements. A Periodic Table will always be given in an exam.

30. Key: hydrogen Electron Neutron Proton  1H H  1

31. Key: helium Electron Neutron Proton  He   4He 2 What is missing from the diagram?

32. Key: helium Electron Neutron Proton  He 4He 2 In Chemistry exams we are only concerned with the number and position of the electrons.

33. fluorine Electron 1. Look-up in the Periodic Table 19F 9 F 2. How many electrons? = 9 3. Draw the electronic structure following the rules Long electronic structure 2,7 1st energy level.2nd energy level.3rd energy level Short electronic structure

34. Key: fluorine Electron Neutron Proton     F      19F  9 What is missing from the diagram?

35. Electronic structure • Using your Periodic Table, complete the worksheet for the first 20 elements • Show for each element its symbol, its long and short electronic structures-where the electrons are in each energy level Check the annotation of your Periodic Tables with the following information: What does the Group number tell you about the electronic structure? What does the Period number tell you about the element?

36. Calculating electron arrangements

37. The periodic table

38. 1 5 0 2 3 6 7 4 Db Rf Ac Ta Fr Cd Sg Ra Bh Rg Mt Ds Hf ? ? ? ? ? ? Hs Re Tc Rh Rn Os Ir Pt Au Hg Tl Pb Bi Pd Po Rb W Sr Y Zr Nb Mo ? Ru At Cs Ag La As V Sb Te I Xe K Ca Ge Ti Sc Cr Mn Fe Co Ni Cu Zn Ga Na Ba Br H Sn In Li Kr Mg Al Si P He S Ar Be Se B C N O F Ne Cl Columns of elements Arranging allthe elements by the number of protons they contained and their properties led to the creation of the periodic table. The elements are organized into groups. groups

39. Electrons and groups In the periodic table, elements are represented by a chemical symbol, for example: • Mg represents magnesium • C represents carbon. Elements in the same group in the periodic table have very similar properties. This is because elements in a group have the same number of electrons in their outer shell and so react in a similar manner. Elements in Group 0 (at the far right of the periodic table) are called the Noble Gases. These elements are very unreactivebecause they have full outer electron shells. They are also referred to as being stable elements.

40. Electronic structure • Using your Periodic Table, complete the worksheet for the first 20 elements • Show for each element its symbol, its long and short electronic structures-where the electrons are in each energy level Annotate your Periodic Tables with the following information: What does the Group number tell you about the electronic structure? What does the Period number tell you about the element? What do all the elements in a group have in common?

41. Elements, mixtures & compounds • Use your Periodic Table to classify the elements • Metals • Non-metals • Gases • Liquids • Group 1 is the Alkali Metals • Group 7 is the Halogens • Group 0 is the Noble Gases • Single atoms are elements • H (hydrogen), Na (sodium), F (fluorine) • Name these elements • Ne, S, Cu, O, Mg, Mn, K, Fe… How are the atoms joined together?

42. Homework-review by next session • Use the next slides in “slideshow mode” • The next two slides is new work on drawing chemical formulae and molecules-have a go • Go over the work from this lesson using the following slides that contain a variety of self-assessment tests and quizzes to establish your understanding

43. Elements, mixtures & compounds • Molecules (another name is compounds) are written as a formula • NaCl (sodium chloride), CuO (copper oxide), CuCO3 (copper carbonate) • Each element is represented once unless it has a suffix number included e.g. CuCO3 there are 3 atoms of oxygen • How many atoms of each element are in these molecules? • Try to name these molecules? • KCl, NaOH, FeS, CH4, FeCl3, Al2O3 • We are now going to draw them! How are the atoms joined together?

44. Elements, mixtures & compounds MgO, CaCO3, KCl, NaOH, FeS, CH4 O Fe S Na H O H Mg O K Cl Ca C O H C H O H Now draw these: Cl2, H2O CaSO4, LiF, Ne, FeCl2, FeCl3 O Cl Cl O Li Cl Ca Ne S Cl Cl O Fe F Fe O H O H Cl Cl

45. Elements Have you completed the electronic structure of the first 20 elements sheet, showing both their long and short versions? Annotate your Periodic Tables with the following information: What do all the elements in a group have in common? What does the Group number tell you about the electronic structure? What does the Period number tell you about the element? Group names Metals and non-metals Liquids

46. The Periodic Table of elements I 0 Group number III IV VI VII II V Why do we use symbols? Period number There are 92 elements found in nature Over 20 man-made elements. A database to show relationships among these elements We are going to make some classifications…..

47. Atoms – true or false?

48. Atomic structure-Learning outcomes • Be able to use the chemical database called the Periodic Table to find an element by its atomic number • Know the structure of the atom in terms of the proton, neutron and electron h) Electrons occupy particular energy levels. Each electron in an atom is at a particular energy level (in a particular shell). The electrons in an atom occupy the lowest available energy levels (innermost available shells). http://www.bbc.co.uk/learningzone/clips/introduction-to-atoms-and-elements/1861.html

49. Trueor false? How to play: Put your hand up for true, leave your hand down for false. Keep track of your score.

50. TRUE The middle of an atom is called the nucleus.