What good is the Periodic Table?

1. What good is the Periodic Table? There is a table provided for your use during the TAKS test, what can it do to help you?

2. What is an element? • Basically, if it is listed anywhere on the periodic table (of the elements) it is an element. • If it is on the left side it is a metal element, if it is on the right side it is a NONmetal element. (Hydrogen is the ONLY nonmetal to the left of the stairstep line.) • Let’s look . . .

3. Where are the metal elements? Left of the Stair-step line!

4. Where are the nonmetals? To the Right of the stair step line, and Hydrogen!

5. Where are the metalloids? • Along the stair step line. • These elements have properties of both metals and nonmetals.

6. The center elements on the table are called the transition metals. Many of them have more than 1 way they will give away electrons, so they change, or transition, ion charges. The charge these metals use are given by a roman numeral in the name. (Iron (II) chloride)

7. The Rare Earth Metals are radioactive and form the bottom 2 rows, also called the Lanthanide and Actinide Series.

8. So, I can tell if it’s a metal or not, what else? • Each column on the table is a group or family of elements that have similar chemical properties. • They form the same types of compounds, in the same ratio. • They have the SAME NUMBER OF OUTER SHELL (valence) electrons. • Lets look . . .

9. Group # 18 is the family called Noble Gases – each one has 8 outer shell electrons (full shell) so they don’t form compounds.

10. Group #1 is called the Alkalai metals, they have 1 valence electron, and will form +1 ions. The are Alkalai because they form the strongest (highest pH) bases.

11. Group #2 is called the Alkalai Earth Metals and they have 2 valence electrons, which they will give away to form +2 ions.

12. Group #17 are the Halogens, they all have 7 electrons in their valence shell, and want to have 1 more when they form compounds. They all become -1 ions when they can.

13. For each group, they form compounds the same way, for example. . . • Beryllium forms a compound with Cl in the ratio of 1:2 or BeCl2 • Since Mg and Ca are in the same family or group, they will form the same type of compounds in the same ratio. • MgCl2 and CaCl2 • This is what is meant when they have “similar chemical properties”

14. Each square also tells us information about each element. • The 1 or 2 letters that represent the element are its symbol. • The number at the top of the square is the atomic number. • The numbers at the bottom of the square is the average atomic mass.

15. What do the numbers mean? This is the atomic number. It is the number of protons in a single atom of this element. By the way, its also # of electrons. 11 Na The symbol for this element. This is the atomic mass, it is the number of protons + neutrons, or the mass of the nucleus of an atom. 22.990 sodium This is the name of the element.

16. Use the table, it will help you answer at least 5 questions! That may be the difference you need to pass!!

17. Now, let’s write some formulas and names • Roll one of each color, the positive ion is written first. • Use the charge as the subscript to the opposite ion, but remove the + or --. • If the ion is a group, DO NOT CHANGE THE GROUP, put it in ( ) with the number as a subscript outside. • To name it, write the name of the + ion, then name the – ion, or if it is an element, change the ending to –ide. Don’t forget the Roman Numeral for transition metals.

18. Law of Conservation of Mass • Matter can not be created or destroyed. • This means if it is on one side of an equation, it must be on the other, and there must be the same number of atoms of that element.