1. Elements

2. Elements, Compounds, and Mixtures
What Do You Think?
How is an element different from a compound?

3. Answer
An element is made up of only one pure substance, and a compound is composed of two or more elements that are chemically combined.
Gold
Water

4. Elements
An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.

5. Elements
A pure substance is a substance in which every particle of that element is the same.
Example: Every particle in a 5g gold nugget is like every other particle of gold, no matter where they are found.

6. Every element has a unique set of properties.
Elements
Every element has a unique set of properties.
The Periodic Table of Elements is arranged according to these properties.

7. Every element has a unique set of properties.
Elements
Every element has a unique set of properties.
Some physical properties that are used to classify elements are boiling point, melting point, color, and density.

8. Elements
Chemical properties used to separate elements from each other include reactivity with acids, or reactivity with oxygen.

9. Elements Are Grouped
Some elements are shiny, and can conduct thermal energy. They are all grouped together on the left hand side of the Periodic Table. They are called metals. Not all metals are exactly alike, but they do have some properties in common.

10. Elements Elements Can Be Identified By Categories Try this!
If you know the category, you know the properties.
Try this!
1. Share with your class how CDs can be classified by categories?
2. How can dogs be classified by categories?

11. Elements are identified by 3 main categories
Metals
Nonmetals
Metalloids
Elements are identified by 3 main categories

12. Elements
Metals
Metals are elements that are usually shiny and good conductors of electricity and heat.

13. Metals are also malleable (can be hammered into thin sheets).
Elements
Metals
Metals are also malleable (can be hammered into thin sheets).

14. Elements
Metals are ductile, or can be drawn into thin wires.
Metals are located to the left of the “zig zag line” on the Periodic Table.

15. Examples: Iron (Fe) and Copper (Cu).
Elements
Examples: Iron (Fe) and Copper (Cu).

16. Click below to see properties of Metals.
Elements
Click below to see properties of Metals.

17. Elements
Nonmetals
Usually dull and poor conductors of heat and electric current.
Tend to be brittle and unmalleable.

18. Elements
Nonmetals
Nonmetals are located to the right of the “zig zag line” on the Periodic Table.

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Elements
Nonmetals
Examples: Neon (Ne) and Carbon (C)
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reluctant-messenger.com/ diamond_sutra.htm

20. Click below to see properties of Nonmetals
Elements
Click below to see properties of Nonmetals

21. Share properties of both metals and nonmetals. Can be shiny or dull.
Elements
Metalloids
Share properties of both metals and nonmetals.
Can be shiny or dull.
Somewhat malleable and ductile.

22. Elements Metalloids touch the “zig zag line” on the Periodic Table.
Examples:
Silicon (Si) Arsenic (As).

23. Click below to see properties of metalloids.
Elements
Click below to see properties of metalloids.

24. Describe some physical properties of the element iron.
Let’s Review!
- 1 -
Describe some physical properties of the element iron.

25. Physical properties include:
Answer
Physical properties include:
Melting Point: °C
Density: 7.9 g/cm3
Iron has the ability to conduct heat and electrical current.

26. Let’s Review
- 2 -
What is an example of a metal that is very malleable, shiny, and is used often in kitchens?

27. Answer
Aluminum Foil

28. What do salt, sugar, baking soda, and water have in common?
Compounds
What Do You Think?
What do salt, sugar, baking soda, and water have in common?

29. Compounds
A compound is a pure substance composed of two or more elements that are chemically combined.
Familiar Compound
Compound
Elements Combined
Table Salt
Sodium and Chlorine
Water
Hydrogen and Oxygen
Sugar
Carbon, Hydrogen, and Oxygen
Carbon Dioxide
Carbon and Oxygen
Baking Soda
Sodium, Hydrogen, Carbon, and Oxygen

30. Properties of Compounds
Compounds, like elements, can be identified by their own physical and chemical properties.
What are some examples of physical and chemical properties?

31. Compounds
Each compound has different properties than the elements that make them up.
Water
Hydrogen
Oxygen
Melting Point
0°C °C °C
Boiling Point
100 °C °C °C
Density
1.0 g/cm3
g/cm3
1.429 g/cm3
State at Room Temperature
Liquid
Gas

32. Compounds are Composed of Elements.
The compound Water is composed of Hydrogen and Oxygen chemically bonded together.

33. Compounds Compounds are Composed of Elements.
The compound Ammonium is composed of Nitrogen and Hydrogen chemically bonded together.

34. What is the difference between an element and a compound?
Let’s Review!
- 1 -
What is the difference between an element and a compound?

35. Answer
An element is a pure substance that cannot be separated into simpler means by physical or chemical means.
A compound is a pure substance composed of two or more elements that can be broken into simpler substances by a chemical change.

36. Make a Venn diagram comparing and contrasting elements and compounds.
Activity for Chapter 2
Elements
Compounds

37. Elements, Compounds, and Mixtures
Pre-AP Extensions for Chapter 2
Mixtures are combinations of two or more elements that are not chemically combined.
Mixtures can be separated into 2 types: homogenous mixtures and heterogenous mixtures.

38. Elements, Compounds, and Mixtures
Homogenous Mixtures
A homogenous mixture is a mixture of two or more substances that is completely uniform in composition.
Homogenous mixtures can be separated by physical means, but it is often difficult to do.
Examples include salt water, kool aid, and air.

39. Elements, Compounds, and Mixtures
Heterogenous Mixtures
A heterogenous mixture consists of many different items, which are often not easily sorted or separated, though they are clearly distinct.
Examples include oil and water mixed together, sand or gravel, and even chocolate chip cookies!

40. Elements, Compounds, and Mixtures
Websites to Visit
Percent Calculations in a Mixture
Chromatography Mixtures Lab

41. Introduction to the Periodic Table
What Do You Think?
How do scientists use physical properties to arrange elements on the periodic table?

42. Introduction to the Periodic Table
Dimitri Mendeleev discovered a pattern to the elements in the periodic table in 1869.
quantique-histoire.htm

43. Introduction to the Periodic Table
He simply wrote the names of all of the elements on cards, along with some of their properties.

44. Introduction to the Periodic Table
Mendeleev tried arranging his cards based on different properties like color, density, melting point, and atomic mass.
He found that by arranging the elements by increasing atomic mass, he found many other properties that fit a pattern.

45. Introduction to the Periodic Table
Mendeleev found that by arranging the elements by increasing atomic mass, similar physical and chemical properties repeated in every 8th element.
This is called periodic, or having a regular, repeating pattern.
Can you think of anything else that is periodic?

46. Why was Mendeleev so important in the study of the periodic table?
Let’s Review!
- 1 -
Why was Mendeleev so important in the study of the periodic table?

47. Answer
Mendeleev was responsible for arranging the periodic table by increasing atomic mass.
This arrangement organizes the table making it easier for us to use.

48. Introduction to the Periodic Table
What Do You Think?
How do scientists use physical properties to arrange elements on the periodic table?

49. Introduction to the Periodic Table
Elements are classified on the periodic table based on their properties.
Like we learned in Chapter 2, we classify them as metals, nonmetals, and metalloids.

50. Introduction to the Periodic Table
Metals
Remember that metals are shiny, ductile, malleable, and are good conductors of thermal energy and electrical current.

51. Introduction to the Periodic Table
Metals
Metals are located to the left of the “zig zag” line on the periodic table.

52. Introduction to the Periodic Table
Physical Properties of Metals
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53. Introduction to the Periodic Table
Chemical Properties of Metals
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54. Introduction to the Periodic Table
Nonmetals
Remember also that nonmetals are not shiny and are poor conductors of thermal energy and electric current.

55. Introduction to the Periodic Table
Nonmetals
Nonmetals are found to the right of the “zig zag” line on the periodic table.

56. Introduction to the Periodic Table
Physical and Chemical Properties of Nonmetals
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57. Introduction to the Periodic Table
Metalloids
Metalloids are elements that have properties of both metals and nonmetals.

58. Introduction to the Periodic Table
Metalloids
Metalloids border the “zig zag” line on the periodic table.

59. Introduction to the Periodic Table
Physical and Chemical Properties of Metalloids
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60. Let’s Review!
- 1 -
Use the properties of metalloids to explain their position on the periodic table.

61. Answer
Metalloids are located between metals and nonmetals because they have properties in between metal and nonmetals.