2. The Periodic Table of Elements

3. Elements  Science has come along way since Aristotle’s theory of Air, Water, Fire, and Earth.  Scientists have identified 92 Natural elements, and created about 28 others.

4. Elements The elements, alone or in combinations, make up our bodies, our world, our sun, and in fact, the entire universe.

5. The most abundant element in the earth’s crust is oxygen.

6. I am Dmitri Mendeleev! I made the PERIODIC TABLE !

7. What is the PERIODIC TABLE? oShows all known elements in the universe. oOrganizes the elements by chemical properties.

8. Periodic Table  A great deal of information about an element can be gathered from its position on the period table.  Understanding the organization and plan of the periodic table will help you obtain basic information about each of the 118 known elements.

9. How do you read the PERIODIC TABLE?

10. What is the ATOMIC NUMBER? oThe number of protons found in the nucleus of an atom Or oThe number of electrons surrounding the nucleus of an atom.

11. What is the SYMBOL? oAn abbreviation of the element name.

12. What is the ATOMIC MASS? oThe number of protons and neutrons in the nucleus of an atom.

13. How do I find the number of protons, electrons, and neutrons in an element using the periodic table? o# of PROTONS = ATOMIC NUMBER o# of ELECTRONS = ATOMIC NUMBER o# of NEUTRONS = Atomic mass number (rounded off) minus the atomic number

14. Periodic Table

15. Metals

16. Properties of Metals Metals appear to the left of the dark ziz-zag line on the periodic table. Most metals are solid at room temperature.

17. Properties of Metals Metals have luster. This means they are shiny

18. Ductile metals can be drawn into wire.

19. Properties of Metals Malleable metals can be h ammered into sheets

20. Metals have a high melting point. They are also very dense.

21. Properties of Metals Conductors Metals are good conductors of electricity and heat

22. When you leave a spoon in a cup of hot drink, the bit poking out of the drink gets hot. Why? Conduction! METALS are the best conductors of heat. This is because the electrons in metals move more freely than in non-metals, allowing the heat energy to travel across the metal. For example, when the spoon touches the hot drink, the heat from the drink excites the electrons in the metal, and the electrons transfer the energy from one electron to another, carrying the heat all the way up the spoon quickly. Best conductors: silver and copper

23. Physical Properties of METALS Metals are good conductors of electricity. Copper, silver, and gold are good electrical conductors. In a conductor, electric current can flow freely. Since metals have free electrons, they can carry a charge easily. Copper Wiring

24. Properties of Metals A chemical property of metal is its reaction with water and oxygen. This results in corrosion and rust.

25. Nonmetals

26. Properties of Nonmetals Nonmetals occur to the right of the dark zig-zag on the periodic table. Although Hydrogen is in family 1, it is also a nonmetal. Many nonmetals are gases at room temperature.

27. Properties of Nonmetals Nonmetals do not have luster; they are dull.

28. Properties of Nonmetals Brittle Nonmetals are brittle so they break easily. This means nonmetals ARE NOT ductile or malleable.

29. Nonmetals have low density.

30. Properties of Nonmetals They also have a low melting point. This is why they are poor conductors of heat and electricity.

31. Metalloids

32. Properties of Metalloids Metalloids can be found clustered around the dark zig-zag line that separates metals and nonmetals.

33. Properties of Metalloids Metalloids (metal- like) have properties of both metals and nonmetals.

34. Properties of Metalloids Metalloids are solids that can be shiny or dull.

35. Properties of Metalloids They conduct electricity and heat better than nonmetals but not as well as metals.

36. Properties of Metalloids Metalloids are malleable and ductile