1. Searching For an Organizing Principle
6.1
Searching For an Organizing Principle
Searching For an Organizing Principle
How did chemists begin to organize the known elements?

2. Searching For an Organizing Principle
6.1
Searching For an Organizing Principle
Chemists used the properties of elements to sort them into groups.

3. Searching For an Organizing Principle
6.1
Searching For an Organizing Principle
Chlorine, bromine, and iodine have very similar chemical properties.
Chlorine, bromine, and iodine have very similar chemical properties. The numbers shown are the average atomic masses for these elements.

4. Mendeleev’s Periodic Table
6.1
Mendeleev’s Periodic Table
Mendeleev’s Periodic Table
How did Mendeleev organize his periodic table?

5. Mendeleev’s Periodic Table
6.1
Mendeleev’s Periodic Table
Mendeleev arranged the elements in his periodic table in order of increasing atomic mass.
The periodic table can be used to predict the properties of undiscovered elements.

6. Mendeleev’s Periodic Table
6.1
Mendeleev’s Periodic Table
An Early Version of Mendeleev’s Periodic Table
In this early version of Mendeleev’s periodic table, the rows contain elements with similar properties. Observing A fourth element is grouped with chlorine (Cl), bromine (Br), and (I) iodine. What is this element’s symbol?

7. The Periodic Law How is the modern periodic table organized? 6.1

8. 6.1
The Periodic Law
In the modern periodic table, elements are arranged in order of increasing atomic number.
In the modern periodic table, the elements are arranged in order of increasing atomic number. Interpreting Diagrams How many elements are there in the second period?

9. 6.1
The Periodic Law
The periodic law: When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
The properties of the elements within a period change as you move across a period from left to right.
The pattern of properties within a period repeats as you move from one period to the next.

10. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metals, Nonmetals, and Metalloids
What are three broad classes of elements?

11. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Three classes of elements are metals, nonmetals, and metalloids.
Across a period, the properties of elements become less metallic and more nonmetallic.

12. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metals, Metalloids, and Nonmetals in the Periodic Table
One way to classify elements in the periodic table is as metals, nonmetals, and metalloids. Inferring What is the purpose for the black stair-step line?

13. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metals, Metalloids, and Nonmetals in the Periodic Table
One way to classify elements in the periodic table is as metals, nonmetals, and metalloids. Inferring What is the purpose for the black stair-step line?

14. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metals, Metalloids, and Nonmetals in the Periodic Table
One way to classify elements in the periodic table is as metals, nonmetals, and metalloids. Inferring What is the purpose for the black stair-step line?

15. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metals, Metalloids, and Nonmetals in the Periodic Table
One way to classify elements in the periodic table is as metals, nonmetals, and metalloids. Inferring What is the purpose for the black stair-step line?

16. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metals
Metals are good conductors of heat and electric current.
80% of elements are metals.
Metals have a high luster, are ductile, and are malleable.

17. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Uses of Iron, Copper, and Aluminum
The metals iron, copper, and aluminum have many important uses. How each metal is used is determined by its properties.

18. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Uses of Iron, Copper, and Aluminum
The metals iron, copper, and aluminum have many important uses. How each metal is used is determined by its properties.

19. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Uses of Iron, Copper, and Aluminum
The metals iron, copper, and aluminum have many important uses. How each metal is used is determined by its properties.

20. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Nonmetals
In general, nonmetals are poor conductors of heat and electric current.
Most nonmetals are gases at room temperature.
A few nonmetals are solids, such as sulfur and phosphorus.
One nonmetal, bromine, is a dark-red liquid.

21. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
Metalloids
A metalloid generally has properties that are similar to those of metals and nonmetals.
The behavior of a metalloid can be controlled by changing conditions.

22. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
If a small amount of boron is mixed with silicon, the mixture is a good conductor of electric current. Silicon can be cut into wafers, and used to make computer chips.

23. 1. The modern periodic table has elements arranged in order of
6.1 Section Quiz
1. The modern periodic table has elements arranged in order of
colors.
melting and boiling points.
increasing atomic mass.
increasing atomic number.

24. 6.1 Section Quiz
2. Mendeleev arranged the elements in his periodic table in order of increasing
atomic number.
number of protons.
number of electrons.
atomic mass

25. 3. Which one of the following is NOT a general property of metals?
6.1 Section Quiz
3. Which one of the following is NOT a general property of metals?
ductility
malleability
having a high luster
poor conductor of heat and electricity

26. END OF SHOW