2. The Periodic Table: Reading the Periodic Table  Each element in the periodic table is represented by its own box, or element key, on the periodic table.

3. The Periodic Table: Reading the Periodic Table  Each element in the periodic table is represented by its own box, or element key, on the periodic table.  In the standard version of the periodic table, the text of the element key contains four basic pieces of information about every element:

4. The Periodic Table: Reading the Periodic Table  Each element in the periodic table is represented by its own box, or element key, on the periodic table.  In the standard version of the periodic table, the text of the element key contains four basic pieces of information about every element:  Symbol  Name  Atomic Number  Atomic Mass

5. The Periodic Table: Reading the Periodic Table  Some periodic tables provided additional information about each element.

6. The Periodic Table: Reading the Periodic Table  Some periodic tables provided additional information about each element.  The symbol for each element is made up of one to three letters.

7. The Periodic Table: Reading the Periodic Table  Some periodic tables provided additional information about each element.  The symbol for each element is made up of one to three letters.  A one-letter symbol, such as H or hydrogen, is capitalized.

8. The Periodic Table: Reading the Periodic Table  Some periodic tables provided additional information about each element.  The symbol for each element is made up of one to three letters.  A one-letter symbol, such as H or hydrogen, is capitalized.  For a two-letter symbol, such as He for helium, only the first letter is capitalized.

9. The Periodic Table: Periods  Each horizontal row of elements from let to right on the periodic table is called a period.

10. The Periodic Table: Periods  Each horizontal row of elements from let to right on the periodic table is called a period.  As you move across a period, the properties of the elements follow a repeating pattern.

11. The Periodic Table: Periods  The atomic number is the number of protons in the nucleus of an element’s atoms.

12. The Periodic Table: Periods  The atomic number is the number of protons in the nucleus of an element’s atoms.  Because atoms are neutral, the number of electrons in an atom is the same as its atomic number.

13. The Periodic Table: Periods  The atomic number is the number of protons in the nucleus of an element’s atoms.  Because atoms are neutral, the number of electrons in an atom is the same as its atomic number.  These electrons are arranged around the nucleus in different orbitals.

14. The Periodic Table: Periods  The atomic number is the number of protons in the nucleus of an element’s atoms.  Because atoms are neutral, the number of electrons in an atom is the same as its atomic number.  These electrons are arranged around the nucleus in different orbitals.  The number of electrons that can be in a particular orbital is limited.

15. The Periodic Table: Periods  The periodic table provides information about the locations of electrons in an atomic of an element based on the period in which the element appears.

16. The Periodic Table: Periods  The periodic table provides information about the locations of electrons in an atomic of an element based on the period in which the element appears.  There are seven periods in the periodic table.

17. The Periodic Table: Periods  The periodic table provides information about the locations of electrons in an atomic of an element based on the period in which the element appears.  There are seven periods in the periodic table.  The two rows at the bottom of the table are actually parts of Periods 6 and 7.

18. The Periodic Table: Periods  The lowest energy level, or first orbital, of an atom can only have two electrons.

19. The Periodic Table: Periods  The lowest energy level, or first orbital, of an atom can only have two electrons.  In the first period of the table has only two elements – hydrogen and helium.

20. The Periodic Table: Periods  The lowest energy level, or first orbital, of an atom can only have two electrons.  In the first period of the table has only two elements – hydrogen and helium.  Hydrogen has one electron and helium has two electrons.

21. The Periodic Table: Periods  The lowest energy level, or first orbital, of an atom can only have two electrons.  In the first period of the table has only two elements – hydrogen and helium.  Hydrogen has one electron and helium has two electrons.  Lithium (atomic number 3) has three electrons.

22. The Periodic Table: Periods  Because the first orbital is filled by the two electrons, the third electron is located in the second orbital.

23. The Periodic Table: Periods  Because the first orbital is filled by the two electrons, the third electron is located in the second orbital.

24. The Periodic Table: Periods  Because the first orbital is filled by the two electrons, the third electron is located in the second orbital.  From left to right across the second period, each element has one additional electron in the second orbital.

25. The Periodic Table: Groups  The periodic table arranges electrons into rows and columns.

26. The Periodic Table: Groups  The periodic table arranges electrons into rows and columns.  A group consists of the elements in a particular column of the periodic table.

27. The Periodic Table: Groups  The periodic table arranges electrons into rows and columns.  A group consists of the elements in a particular column of the periodic table.  The elements in a group have similar chemical and physical properties.

28. The Periodic Table: Groups  All of the elements in each group have the same arrangement of electrons in their highest orbitals.

29. The Periodic Table: Groups  All of the elements in each group have the same arrangement of electrons in their highest orbitals.  At the top of the periodic table, the groups are labeled with the numbers 1 through 18.

30. The Periodic Table: Groups  All of the elements in each group have the same arrangement of electrons in their highest orbitals.  At the top of the periodic table, the groups are labeled with the numbers 1 through 18.  A second set of labels shows an alternative group- labeling systems that uses Roman numerals I-VIII and letters A and B.