1. 1.There are billions of materials in our universe. 2.Those materials are made up from about 100 elements only. Atoms and Elements

2. An element is a substance that is made from one kind of atom only. It cannot be broken down into simpler substances. An element atom

3. A substance made from only one type of atom is a MOLECULE, and because all the atoms are the same, it is still an element.

4. Molecules can also be substances made from more than one element. (These are also called compounds) atom A molecule made up of 2 different elements A molecule made up of 7 different elements

5. A molecule that is a compound can be broken down into elements A molecule made up of 3 different elements An element

6. Molecules A molecule can be made from the same type of atom, or two or more different types of atoms ( a compound) These can be broken down into individual elements. Methane CH 4 Chlorine Cl 2 Remember, all compounds are molecules but not all molecules are compounds

7. Chemical formulas These are used to represent molecules and indicate the type and number of elements that make up the molecule.

8. Rules for chemical symbols in the periodic table: 1.The symbol is usually the first one or two letters of the name. 2.Sometimes the old (Latin) name is used. 3.The first letter of a symbol is always a capital letter. 4.The second letter of a symbol is always a small letter. 5.Every element has a different symbol.

9. Numbers are used to represent how many of each element are present in the formula. The numbers are written to the right of the element as a subscript (smaller and lower down) H 2 O This tells us there are 2 atoms of hydrogen and only 1 atom of oxygen.

10. What is a molecule? A) Atoms separated by tiny spaces B) Two or more atoms bonded together C) Only ever made of the same type of atom. D) Something that must always contain carbon

11. What is a molecule? A) Atoms separated by tiny spaces B) Two or more atoms bonded together C) Only ever made of the same type of atom. D) Something that must always contain carbon

12. How many of each atom are in the following formulas. HCl Cl 2 CO 2 CH 4

13. How many of each atom are in the following formulas. HCl 1 hydrogen and 1 chlorine Cl 2 2 chlorine CO 2 1 carbon 2 oxygen CH 4 1 carbon 4 hydrogen

14. Now look in your periodic table and find name that corresponds to the following symbol: Fe …….. Mg ……….. Ag ……….. K ……….. C ………… Ca ……. Na ………. N ……… Ne …….. Pb ……….

15. Now look in your periodic table and find the symbols of the following elements, then find out if it is a metal or a non- metal: Copper Cu Iron …Fe Magnesium …Mg Chlorine …Cl Carbon ……C Sodium …Na Lead …Pb Gold …Au Calcium …Ca Fluorine …F

17. Now look in your periodic table and find if each is a metal or a non-metal: Copper ………….. Iron …………….. Magnesium …………….. Chlorine …………….. Carbon …………….. Sodium …………….. Lead …………….. Gold …………….. Calcium ………… Fluorine …………..

18. Now look in your periodic table and find out if each is a metal or a non-metal: Copper …metal Iron …metal Magnesium …metal Chlorine …non-metal Carbon …non-metal Sodium …metal Lead …metal Gold …metal Calcium …metal Fluorine …non- metal