1. Investigation III: A Particulate World
Alchemy Unit
Investigation III: A Particulate World
Lesson 1: Pudding and Clouds
Lesson 2: Building Atoms
Lesson 3: Subatomic Heavyweights
Lesson 4: Life on the Edge
Lesson 5: Shell Game
Lesson 6: Go Figure
Lesson 7: Technicolor Atoms

2. Alchemy Unit – Investigation III
Lesson 1:
Pudding and Clouds

3. Periodic Table Groups
Group 1- Alkali Metals- these are very reactive. Have even been know to explode when water touches them.
Sodium Carbonate
Unit 1 • Investigation III

4. Group 2- Alkaline Earth Metals
Periodic Table Groups
Group 2- Alkaline Earth Metals
They are not nearly as reactive as Group 1 but will form bonds easily.
Radium can be found in glow-in–the-dark paint
Unit 1 • Investigation III

5. This group will not form bonds with other atoms.
Periodic Table Groups
Group 6- Noble Gases
This group will not form bonds with other atoms.
Unit 1 • Investigation III

6. ChemCatalyst
In the 5th century BCE a Greek philosopher named Leucippus and his student, Democritis, stated, “All matter is made up of particles that can’t be divided called atoms.”
What do you think atoms are?
Unit 1 • Investigation III

7. The Big Question
How have chemists thought about the atom through history?
Unit 1 • Investigation III

8. You will be able to:
Describe some models of an atom and explain how they differ.
Unit 1 • Investigation III

9. Notes
Atoms are extremely small particles, which cannot be seen, even with microscopes.
All matter is made up of atoms.
Scientists have created models to describe atoms. Models are similar to theories, but often include a picture or physical representation.
(cont.)
Unit 1 • Investigation III

10. As new evidence is gathered, models are refined and changed.
(cont.)
Scientific evidence is a collection of observations that many people have made. Everyone agrees on the same collection of observations.
When a model is supported by scientific evidence it is often accepted by the scientific community.
As new evidence is gathered, models are refined and changed.
Unit 1 • Investigation III

11. Parts of the Atom
A proton is a positively charged particle that exists in the nucleus.
A neutron is a neutral particle with no charge on it that exists in the nucleus
The electron is a negatively charged particle that exists in an electron cloud around the nucleus.
(cont.)
Unit 1 • Investigation III

12. The Nucleus An atom is mostly empty space.
There is the nucleus, which is located in the very center of the atom.
The nucleus is very small. .
The nucleus is also very dense and consists of two types of particles—neutrons and protons.
(cont.)
Unit 1 • Investigation III

13. A cloud around the nucleus where the electrons can be found.
Electron Cloud
A cloud around the nucleus where the electrons can be found.
Unit 1 • Investigation III

14. Notes (cont.)
Unit 1 • Investigation III

15. Activity
Purpose: This lesson will introduce you to various models for the atom that have appeared over the past two hundred years. The descriptions of five models of the atom are on a separate handout.
(cont.)
Unit 1 • Investigation III

16. Theories of the Atom
The History of the Atom

17. Atoms can not be divided into smaller pieces
John Daltons Theory
Matter is made of atoms
Atoms can not be divided into smaller pieces
Unit 1 • Investigation III

18. Different elements are made of different kinds of atoms
All atoms of an element are exactly alike
Unit 1 • Investigation III

19. John Dalton thought that atoms looked like solid spheres.
Unit 1 • Investigation III

20. J.J. Thomson
Thought that the atom is a sphere of positive charge with negative charges spread equally throughout. Therefore, atoms have a neutral charge.
Unit 1 • Investigation III

21. Ernest Rutherford
Thought that the atom had a nucleus (center) that was all positive charge and electrons (negative) that float around it.
Unit 1 • Investigation III

22. Neil Bohr
Atoms have three particles protons, neutrons and electrons. Electrons exist in shells or energy levels around the nucleus.
Unit 1 • Investigation III

23. Current Nuclear Model
Atoms has three types of particles and the electrons exist in an electron cloud.
Protons (positive)
Neutrons (neutral)
Electrons (negative)
Unit 1 • Investigation III

24. Making Sense
From Pudding & Clouds: Examine the date of the atomic evidence and then put the five models in the correct order of their introduction to the world of science.
Unit 1 • Investigation III

25. (cont.)
Five Models of the Atom
Unit 1 • Investigation III

26. Check-Out Here is a Bohr model of a carbon atom.
List two things this model tells you about atoms.
List something this model does not tell you about atoms.
Unit 1 • Investigation III

27. History of the Atom Foldable
Create a tri-fold with the following information:
Each Scientists idea of the atom including the persons name, description of what they thought and a picture of their idea of the atom.
Must be colorful and displayable!
Will be collected and graded!!
Unit 1 • Investigation III

28. Wrap-Up
All matter is made up of extremely small particles called atoms. These particles are too small to be seen even with a microscope.
Science is theoretical and dynamic. Models and theories are continually being revised, refined, or replaced with new models and theories.
Unit 1 • Investigation III

29. Alchemy Unit – Investigation III
Lesson 2:
Building Atoms

30. Copy these questions into your journal.
Look at the following pictures and list three similarities and three differences.
Unit 1 • Investigation III

31. ChemCatalyst
A Bohr model of a helium atom and a beryllium atom are given below.
Helium, He
Berylium, Be
(cont.)
Unit 1 • Investigation III

32. The Big Question
What does the periodic table tell us about the structures of different atoms?
Unit 1 • Investigation III

33. You will be able to:
Use the periodic table to identify the properties of an elements atom.
Unit 1 • Investigation III

34. Atomic Number
Atomic number is the number of protons in the nucleus of an atom. This number is above the chemical symbol.
The number of electrons is always equal to the number of protons in a neutral atom.
Ex. Lithium has 3 protons, therefore it also has 3 electrons
Unit 1 • Investigation III

35. Mass Number
Mass number is the number of protons plus the number of neutrons.
You can find this by rounding the number beneath the chemical symbol.
Also referred to as atomic mass because it is the mass of one atom of the element.
Unit 1 • Investigation III

36. Atomic Weight
1. Atomic Weight is the decimal number that is found beneath the chemical symbol for an element.
2. It is an average of all the different types of atoms for that element.
Unit 1 • Investigation III

37. Calculating the parts of the atom
Mass number (# of protons + neutrons)
minus
Atomic Number (# of protons)
____________________________
Number of neutrons
Unit 1 • Investigation III

38. How to read and use an element key
Unit 1 • Investigation III

39. Activity
Purpose: Label where the protons, neutrons and electrons are in these atoms.
Beryllium Atom
Fluorine Atom
Carbon Atom
(cont.)
Unit 1 • Investigation III

40. (cont.) element chemical symbol atomic number # of protons
# of electrons
# of neutrons
mass number
atomic weight
beryllium 5
fluorine 10 6 12
chlorine 18
35.45
lead
126
potassium 19 39
tin 70
tungsten
184
183.85 29 36
gold
118
Unit 1 • Investigation III

41. Making Sense
If you know the atomic number of an element, what other information can you figure out about the atoms of that element?
If you know the atomic number of an element, can you figure out how many neutrons an atom of that element has? Can you come up with a close guess? Explain.
Unit 1 • Investigation III

42. Bohrs Models

43. How to draw a Bohrs Model
First, find the number of protons, neutrons and electrons
Draw a nucleus
Look at the period. This is the number of shells the atom will have.
Ex. Elements in Period 2 have two shells
Unit 1 • Investigation III

44. Continued
Look at the Group Number, this will tell you the number of electrons in the last (outer) shell
Unit 1 • Investigation III

45. Rules for Bohrs Models
There is a maximum amount of electrons that can exist on each level.
Shell # 1 (next to the nucleus) can only have up to two electrons
Shell # 2 can only have up to 8 electrons
Shell # 3 can only have up to 18 electrons
Shell # 4 can only have up to 32 electrons
Unit 1 • Investigation III

46. Check-Out
1. Use your periodic table to identify the following elements:
a) Atomic number 18
b) Has three electrons
c) Atomic mass of 16.0
2. How do you think a gold atom is different from a copper atom?
Unit 1 • Investigation III

47. Wrap-Up
Each successive element has one more proton than the element preceding it.
The atomic number is equal to the number of protons.
(cont.)
Unit 1 • Investigation III

48. (cont.)
The number of electrons is equal to the number of protons (as long as the atom is neutral).
The mass number is equal to the number of protons plus the number of neutrons (most of the mass is found in the nucleus).
Unit 1 • Investigation III

49. Alchemy Unit – Investigation III
Lesson 4:
Life on the Edge

50. ChemCatalyst
The three atoms below have similar reactivity and chemical behavior.
Where are these elements located on the periodic table?
What do you think might be responsible for their similar properties?
(cont.)
Unit 1 • Investigation III

51. (cont.)
Unit 1 • Investigation III

52. The Big Question
What accounts for the similar chemistry of elements in the same group?
Unit 1 • Investigation III

53. You will be able to:
Give the number of valence electrons for an element.
Unit 1 • Investigation III

54. Activity
Purpose: The various physical and chemical properties of the elements can be traced to the electrons. By studying electrons further we may be able to unlock the key to creating substances similar to gold. This lesson will reveal the arrangement of electrons within atoms.
Unit 1 • Investigation III

55. (cont.)
Five Models of the Atom
Unit 1 • Investigation III

56. Making Sense
Explain how you can determine the arrangement of an element’s electrons, from the element’s position on the periodic table.
Unit 1 • Investigation III

57. Notes
Bohr proposed that electrons could be found in different shells around the nucleus.
Unit 1 • Investigation III

58. (cont.)
(cont.)
Unit 1 • Investigation III

59. The outermost shell of each drawing is called the valence shell.
(cont.)
The outermost shell of each drawing is called the valence shell.
The valence shell contains the valence electrons.
All other electrons are considered core electrons.
Unit 1 • Investigation III

60. Check-In Provide the following information for element number 34.
a) The element’s name and symbol.
b) The number of protons in the nucleus.
c) The total number of electrons for this element.
d) The number of core electrons for this element.
(cont.)
Unit 1 • Investigation III

61. e) The number of valence electrons.
(cont.)
e) The number of valence electrons.
f) The group number for this element.
g) The names of other elements with similar chemistry.
Unit 1 • Investigation III

62. Wrap-Up
Electrons occupy different shells around the nucleus of an atom.
Each electron shell can hold a specific maximum number of electrons.
The valence electrons are in the outermost electron shell of an atom. Electrons that are not valence electrons are called core electrons.
(cont.)
Unit 1 • Investigation III

63. Elements with the same number of valence electrons have similar chemistry and are in the same group.
Unit 1 • Investigation III