1. Atom ,Atomic structure and Chemical Bonding

Power point presentation on Atomic structure and bonding

1. CHEMISTRY YEAR 9 ATOMIC STRUCTURE 6TH SEPTEMBER 2023

2. KEYWORDS

3. Particle Mass Charge Neutron 1 Proton 1 +1 Electron 1/2000 -1

4. Atom Skits(Activity) Materials !"Diagram of an atom Directions With a diagram of an atom and discuss the parts of the atom. Put the students in smaller groups !"Have each group create a skit about the parts of the atom.Students to think about ways to make the atom parts come alive. For example, Mr. Proton and Ms. Neutron could live in a house together, and Mr. Proton could say only 'positive' comments, while Ms. Neutron is 'neutral' about every decision. !"When the groups are !nished, have them present their skits to the class. Discussion Questions !"How are protons, electrons, and neutrons similar and different? \"Why is it important to understand the structure of an atom?

5. ATOM

6. Differences between the parts Proton Charge: Positive + Location: Nucleus Role in the atom: Helps identify the element Neutron Charge: 0 Location: Nucleus Role in the atom: Help hold everything together Electron Charge: Negative - Location: Outside of the Nucleus Role in the atom: Chemical reactivity of the atom

7. L1 Atoms, elements, molecules, compounds, mixtures Lesson objectives Learn the differences between atoms, elements, compound, molecules and mixtures. L e arn about the different atomic models that describe the structure of atoms. Lesson objectives

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9. Use a periodic table to help with the names here. Write down the materials and say whether they are an element, mixture, compound, molecule etc. R e member, sometimes they can be multiple of these… NaCl and H 2 O Silver metal Ag Nitrogen gas N 2 Potassium Bromide KBr Methane CH 4 Platinum metal Pt Xenon gas Xe Air O 2 and CO 2 Ar H 2 Hydrogen gas

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11. Development of the atomic theory. L.O Describe how each scientist contributed to the development of the atomic model.

12. Beginning of Atomic Models History of the model of atoms. The ancient Greeks believed that it you kept cutting something in half to smaller and smaller sizes, you would get down to the smallest possible block of a material. They called this an “atom” meaning “indivisible” (undividable). This model remains until just a couple of hundred years ago…

13. Task Describe how each scientist contributed to the development of the atomic model. Include descriptions of their experiments and what they discovered. 1. John Dalton 2. J.J Thompson 3. Ernest Rutherford 4. James Chadwick 5. Niels Bohr. Include their photos. Their date of birth Pictures of their experiments. One paragraph describing their experiments about the atoms.

14. Instructions! Create a poster on Canva Write a Biography about the scientist assigned that should include : Timelines, birth/death dates, and nationality -Provide a brief introduction to atomic structure and its importance in understanding the composition of matter.   Their Contributions and Experiments: - Describe the key experiments conducted by each scientist and how they contributed to the development of atomic models; - Explain the discoveries and observations made during their experiments. Include pictures of their experiments. .Discuss how these models led to the current understanding of atomic structure.  -Reflect on the importance of their discoveries and how they have shaped our understanding of matter .

15. 1. John Dalton: Rebeccah , Aniya, Ying Ying 2. J.J Thompson: Raymond, Johnson 3. Ernest Rutherford: Leo,Hanhan Lyra 4. James Chadwick: David,Jake,Tiger 5. Niels Bohr: India and Jenny

16. The Dalton Model In 1803, John Dalton put his ideas forward about atoms. H e suggested that substances were made up of atoms that were like tiny, hard spheres. Atoms cannot be created or destroyed. He also came up with the idea that atoms of different elements combine in whole ratios to form chemical compounds Each chemical element had its own atoms that differed from others in their mass.

17. The plum-pudding: In 1897, a scientist called J.J. Thomson discovered the electron. Thomson did experiments on beams of particles. They were attracted to a positive charge, showing they must be negatively charged. He called these electrons. He said that these negatively charged particles must have come from within the atom itself. Since the overall charge of an atom must be zero, he concluded that the electrons were within a cloud of positive charge. He thought that the atoms itself was mostly positive and negative electrons wandered around the atom

18. Rutherford’s atom Ernest Rutherford 1909 Ernest Rutherford was another scientist that changed the atomic model. He felt that J.J. Thomson's model was incorrect, so he created a new one. He created the nucleus , and said that instead of the positive matter being the whole atom, it was just in the middle. He said the atom was mostly empty space and that the electrons surrounded the positive nucleus. This model influenced one of his own students to perfect the atomic model later on.

19. Bohr shell model: The next important development came in 1914, when Niels Bohr revised the atomic model again. He noticed that the light given out when atoms were heated and the light only had specific amounts of energy (certain colours). He suggested that the electrons must be orbiting the nucleus at set distances, in certain fixed energy levels (or shells). The energy must be given out when ‘excited’ electrons fall from a high to a low energy level and matched his predictions from calculations made.

20. Chadwick discovers neutron: Scientists at this time speculated that there was two sub-atomic particles inside the nucleus. They had evidence of protons. But the existence of a second sub-atomic particle in the nucleus was proposed to explain the missing mass that had been noticed in atoms. Because neutrons have no charge, it was very difficult to detect them in experiments. It was not until 1932 that James Chadwick did an experiment that could only be explained by the existence of neutrons! Extra: How do we know how many neutrons are present in an atom?   L1 Atoms, elements, molecules, compounds, mixtures

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22. Give two ways in which Rutherford changed Thomson’s model of the atom Which sub-atomic particle did J.J. Thomson discover?

23. LEARNING OBJECTIVES How the periodic table is ordered. What chemical symbols are and the mass number, atomic number etc What the rows and columns on the periodic table mean and what they represent. To determine the electron configuration of elements and their ions for the first 20 elements.

24. What is a periodic table? What does it look the way it does? Do you notice anything about the elements on the left side and the middle compared to the right side?

25. Rows Periods The Elements are grouped in Rows =Periods The Elements are also grouped in columns= Groups

26. The Periodic Table 20th Sep 2023 Lesson objectives: Define what an isotope is. Learn that atoms try to obtain a full outer shell by gaining or losing electrons Define what an ion is and which elements form positive and negative ions. Draw electron configurations for ions. Lesson objectives

27. Groups and periods – key points In the periodic table, the vertical columns are called groups The horizontal rows of the periodic table are called periods

28. Periods All the elements in a period have the same number of shells E.g. All the elements in the first row (the second period) have two shell for their electrons.

29. QUICK CHECK : Group & period? Bromine group period

30. group period QUICK CHECK: Group & period? Calcium

31. group period QUICK CHECK: Group & period? Neon

32. Where are the alkali metals? The elements in group 1, on the left of the periodic table, are called the alkali metals . lithium sodium potassium rubidium caesium francium Fr Cs Rb K Na Li

33. Group 7 – the halogens The elements in group 7 of the periodic table, on the right, are called the halogens . Halogens are very reactive non metals. fluorine chlorine bromine iodine astatine I Br Cl F At

34. Electron shells All the elements in a vertical group have the same number of electrons in the outer shell. Elements in Group 1 have 1 electron in the outer shell. Elements in Group 2 have 2 electrons in the outer shell. Elements in Group 3 have 3 electrons in the outer shell. Elements in Group 4 have 4 electrons in the outer shell. So the group number equals the number of electrons in the outer shell.

35. The Periodic Table 2 Atoms want to have a full outer shell (for stability). For example, lithium, sodium and potassium have 1 electron in their outer shell. They w an t to LOSE that electron so they have a full outer shell. What about an oxygen atom? What about chlorine?

36. Electron structure All alkali metals have 1 electron in their outer shell. This means that: lithium 2,1 sodium 2,8,1 potassium 2,8,8,1 They can easily obtain a full outer shell by losing 1 electron. They have similar physical and chemical properties. They all lose their outer shell electron in reactions to form positive ions with a +1 charge.

37. All halogens have seven electrons in their outer shell. This means that: What is the electron structure of the halogens? fluorine 2,7 chlorine 2,8,7 bromine 2,8,8,7 They can easily obtain a full outer shell by gaining one electron. They have similar chemical properties. They all gain an electron in reactions to form negative ions with a -1 charge.

38. L3 The Periodic Table 2 When an atom gains or loses an electron, we call it an “ion”. Postive ions are called cations . Negative ions are called anions . Important: An ion is a charged particle. When atoms lose or gain electrons they form ions. 1+ 2- {2} {2,8}

39. Losing electrons to form positive ions… x x xx xx xx x 2,8,1 Sodium Na Na + 2,8 A sodium atom has 11 protons and so 11 electrons. It needs to lose one electron to get a full outer shell. The sodium ion still has 11 protons in its nucleus but now has only 10 electrons. 11 positive protons – 10 negative electrons = +1 charge Electronic configuration xx

40. GROUP 1:THE ALKALI METALS

41. Losing electrons to form positive ions… A calcium atom has 20 protons and so 20 electrons. It needs to lose two electrons to get a full outer shell. The calcium ion still has 20 protons in its nucleus but now has only 18 electrons. 20 positive protons – 18 negative electrons = +2 charge 2,8,8,2 Calcium Ca 2+ 2,8,8 x x xx xx xx Ca xx x x Electronic configuration xx xx xx xx

42. Gaining electrons to form negative ions… A chlorine atom has 17 protons and so 17 electrons. It needs to gain one electron to get a full outer shell. The chloride ion still has 17 protons in its nucleus but now has 18 electrons. 17 positive protons – 18 negative electrons = -1 charge x x xx xx xx x 2,8,7 Chlorine Cl Cl - 2,8,8 x Electronic configuration xx xx xx xx

43. HALOGENS GROUP 7

44. Gaining electrons to form negative ions… A oxygen atom has 8 protons and so 8 electrons. It needs to gain two electrons to get a full outer shell. The oxide ion still has 8 protons in its nucleus but now has 10 electrons. 8 positive protons – 10 negative electrons = -2 charge x x 2,6 Oxygen O O 2- 2,8 Electronic configuration xx xx xx xx

45. NOBLE GASES

46. A match made in heaven… Metal atoms want to lose electrons… Non-metals atom want to gain electrons… For example, A sodium atom is desperate to lose an electron… A chlorine atom is desperate to gain an electron… Na + Cl -

47. L3 The Periodic Table 2 What ion is formed, and draw and write out the electron configuration, when these become ions… Sodium  Potassium Beryllium Chlorine Sulfur Aluminium What happens with argon??? You try some Na + {2,8}, cation

48. L3 The Periodic Table 2 What ion is formed, and draw and write out the electron configuration, when these become ions… Sodium Potassium  Beryllium Chlorine Sulfur  Aluminium What happens with argon??? You try some 2- K Nothing – it already has a full outer shell

49. One more definition to go… An ISOTOPE is an atom of the same element with a different number of NEUTRONS. L3 The Periodic Table 2 Key fact 3 for the day Isotopes. The number of protons defines the element, but different atoms of the same element can have a different number of NEUTRONS. For example, and are isotopes of each other. The only difference is that has 2 more neutrons.  

50. L2 The Periodic Table 1 Today’s key facts You tell me – what are your top 5 facts? Summary facts

51. L3 The Periodic Table 2 What to atoms want with regards to their electron shells? What sort of ions do metal atoms form? Give an example of a 2+ ion in the first 20 elements. Name 3 elements that will naturally form anions. Make sure one is from the first 20 elements and draw the electron configuration for the anion. Thinking ahead. Do you think it’s easier for an atom to lose 1 or 2 electrons? Plenary

52. Home work Research work Know the properties of: Ceramics Malia,Chloe Anna,Nikki Polymers. Geoge, Carlaton,Yang Composites: Emily Joanna and Lily,Mark

53. PROPERTIES OF ELEMENTS We all belong to some group , like a family. If we look at the members of a family, they have something in common. It might be a big nose or ears etc… The periodic table is a huge collection of elements. And It can be divided into families of element.

54. Watch reactions of Group 1 Elements with water