1. Page 30: Counting Elements and Atoms Practice Page 31: Review of Elements and Compounds

2. H2OH2O C 6 H 12 O 6 S

3. ElementsElements Elements--- a pure substance (made up of ONLY ONE type of atom) that cannot be broken down into smaller parts Elements are found on the Periodic Table To count elements, COUNT CAPITAL LETTERS!

4. Compound Compound--- two or more elements that are CHEMICALLY COMBINED H 2 O (2 atoms Hydrogen and 1 atom Oxygen) CaCO 3 (1 atom Calcium, 1 atom Carbon, and 3 atoms Oxygen) CO 2 (1 atom Carbon and 2 atoms Oxygen)

5. Atoms vs. Elements Atoms = particles – The number of atoms is the number of total particles (counting the subscripts AKA little numbers at the bottom) Element = the type of pure substance – The number of elements is the number of capital letters or symbols in your formula.

6. Element VS Compound Zn Mg H P Li O H H Cl Na O O C

7. Is it an element or compound? Ask Yourself? Is there more than one type of element? YES NO

8. Page 30: Counting Elements and Atoms Practice Glue in the example. To the side of the box or below it, include: The number of elements present & their name The number of atoms of each element The TOTAL number of atoms in all.

9. CompoundElements Present# of Atoms eachTotal # of atoms 1. CaCO 3 3: Calcium, Carbon, Oxygen 1 Calcium 1 Carbon 3 Oxygen 5 total atoms 2. C 9 H 8 O 4 3: Carbon, Hydrogen, Oxygen 9 Carbon 8 Hydrogen 4 Oxygen 21 total atoms 3. Mg(OH) 2 3: Magnesium, Oxygen, Hydrogen 1 Magnesium 2 Oxygen 2 Hydrogen 5 total atoms 4. C 6 H 4 Cl 2 3: Carbon, Hydrogen, Chlorine 6 Carbon 4 Hydrogen 2 Chlorine 12 total atoms

10. Compound# of Elements Present # of Atoms of eachTotal # of Atoms 5. C 2 H 4 O 2 3 Elements: Carbon, Hydrogen, Oxygen 2 Carbon 4 Hydrogen 2 Oxygen 8 total atoms 6. C 7 H 5 (NO 2 ) 3 4 Elements: Carbon, Hydrogen, Nitrogen, Oxygen 7 Carbon 5 Hydrogen 3 Nitrogen 6 Oxygen 21 total atoms 7. Ca(H 2 PO 4 ) 2 4 Elements: Calcium, Hydrogen, Phosphorus, Oxygen 1 Calcium 4 Hydrogen 2 Phosphorus 8 Oxygen 15 total atoms 8. FeS 2 2 Elements: Iron and Sulfur 1 Iron 2 Sulfur 3 total atoms