How to Read the Periodic Table

2. How to Read the Periodic Table

3. The Periodic Table Is . . • A table of all known elements, • A useful tool for scientists, • And, it arranges elements according to their properties.

4. The Inventor • Created by Dmitri Mendeleev. • Mendeleev was a teacher who was discouraged by his teaching tools and decided to create his own. • He made note cards of the elements known at that time and arranged them. When there wasn’t an element to fit a certain spot, he left it open and predicted an element would be found later to fill it.

5. Reading a Periodic Table • When reading a periodic table . . . . • Look at the box • Look at the columns (group or family) • Look at the rows (periods) • Look at the location of metals, nonmetals, and semiconductors (metalloids)

6. Using the Box • Each box represents a different element. • Each box contains information that tells . . • The elements name • The elements symbol • The atomic number of the element • The atomic mass of the element

7. Oxygen 8 O 16.00 Example • Name – Oxygen • Atomic Number – 8 • Atomic Symbol – O • Atomic Mass – 16.00

8. Element Names • Some elements are named after places. • Four of the elements are named after planets. • Many elements are named after famous scientists. The scientist’s last name is used along with the ending “ium”.

9. More Element Names • What element has the same name as one of our coins? • What element has the same name as the fictional planet from which Superman came? • What element was named after Thor, the Scandinavian god of war?

10. Element Symbols • An element symbol is an abbreviation for the name of an element. • A symbol can have one or two letters. The first letter of a symbol is always capitalized. The second letter (if there is one) is never capitalized. • Symbols for the naming of elements are part of an international language. Chemists all over the world use the same symbols.

11. More Element Symbols • For most of the elements it’s easy to see where the symbols came from by looking at the names of the elements. The symbol seems to be a combination of one or two of the beginning letters in the element’s name. • Some elements have symbols that come from their Latin names.

12. Using the Columns • Each column of elements is called a family or group. • Elements in a family have similar but not identical properties. • The number for the column sometimes indicates the number of electrons in outer shell of the element (valence electrons). • Elements in a group have the same number of electrons in their outer orbital.

13. Families or Groups • Elements in the red group have 1 electron in their outer shell. • Elements in the orange group have 2 electrons in their outer shell. • As you keep counting the colored columns, you add an additional electron. • Purple has 8 electrons in its outer shell. • (Don’t include the white group)

14. Using the Rows • Rows represent an elements period. • Elements in a period are not alike in properties. • Even though some squares are skipped in between, all of the rows go from left to right.

15. Using the Rows • As a rule. . . . • the first element in a period is usually an active solid. • the last element in a period is always a noble gas. • Atomic size decreases from left to right across a period. • And generally, atomic mass increases from left to right across a period, although there are exceptions.

16. Example • Every element in the top row (first period) has one orbital for its electrons. • Every element in the second row (the second period) has two orbitals available. • Atoms on the left are usually larger and lighter. • Atoms on the right are usually smaller and heavier.

17. Metals, Nonmetals, and Semiconductors Some periodic tables are color coded to show what elements are metals, nonmetals, and semiconductors. In general, elements located in the left two-thirds or so of the periodic table are metals. The nonmetals are on the right side of the table. The dividing line between the metals and nonmetals are elements called semiconductors or metalloids.

18. The gray area represents the metals. The yellow area represents the semiconductors. The blue area represents the nonmetals.

19. Conclusion • The Periodic Table is an excellent tool for looking at elements and the key to using it is to understand the code of it structure. • Using the boxes, columns, and rows will help you learn about the properties of elements.