1. Atoms and Compounds ICS III Week 4

3. How to read the Periodic Table

4. All Atoms Have Mass Mass number Mass number The total number of protons and neutrons in an element The total number of protons and neutrons in an element Each proton and neutron have an average mass of about 1 amu (atomic mass unit) Each proton and neutron have an average mass of about 1 amu (atomic mass unit) 6 protons and 6 neutrons 6 protons and 6 neutrons 12.01 or 12 12.01 or 12 Atomic Mass Unit Atomic Mass Unit A weighted average mass of the atoms in a naturally occurring sample A weighted average mass of the atoms in a naturally occurring sample

5. Practice with mass numbers What is the mass number for Sodium? What is the mass number for Sodium? 22.99 or 23 22.99 or 23 What is the mass number for Oxygen? What is the mass number for Oxygen? 16.00 or 16 16.00 or 16 What is the mass number for Hydrogen? What is the mass number for Hydrogen? 1.01 or 1 1.01 or 1

6. Elements vs. Compounds Element Element Simplest form of matter. Simplest form of matter. Can not be broken down Can not be broken down Compound Compound Substance that contains two or more elements chemically combined in a fixed proportion Substance that contains two or more elements chemically combined in a fixed proportion

7. Element vs. Compound O The element oxygen The element oxygen O 2 O 2 The compound dioxide (two oxygen) The compound dioxide (two oxygen) Contains 2 oxygen elements bonded together Contains 2 oxygen elements bonded together

8. Element vs. Compound 2 Hydrogen elements (H) + 1 Oxygen (O) element 2 Hydrogen elements (H) + 1 Oxygen (O) element H 2 O H 2 O 1 Carbon elements (C) + 2 Oxygen (O) element 1 Carbon elements (C) + 2 Oxygen (O) element CO 2 CO 2

9. How to find the molecular mass of a compound Molecular Mass Molecular Mass Molecular Weight Molecular Weight All matter has mass, or weight All matter has mass, or weight The sum of the atomic masses of the atoms of each element The sum of the atomic masses of the atoms of each element What is the molecular weight of CO 2 ?

10. How to find the atomic mass of a compound CO 2 CO 2 1 Carbon atom 1 Carbon atom 1 x 12 = 12 1 x 12 = 12 2 Oxygen atoms 2 Oxygen atoms 2 x 16 = 32 2 x 16 = 32 CO 2 CO 2 12 + 32 = 44 12 + 32 = 44

11. How to find the atomic mass of a compound Find the atomic mass of H 2 O. Find the atomic mass of H 2 O. 18 18 Find the atomic mass of NaCl. Find the atomic mass of NaCl. 58 58 Find the atomic mass of C 6 H 12 O 6. Find the atomic mass of C 6 H 12 O 6. 180 180

12. Mass of compounds 1617 18 362

13. Amount vs. Weight Substanceamountunitsweight Apples 1 dozen 12 555 grams Donuts 1 dozen 12 250 grams Feathers 1 dozen 12 5 grams Bricks 1 dozen 12 10,000 g What do all these substances have in common?? Amount…… 1 dozen or 12 units Conversion factor????????? What is different about all these substances??? The weight….

14. Mole The number of atoms in 12 grams of carbon-12. The number of atoms in 12 grams of carbon-12. The atomic mass of an element is the weighted average of the mass of one mole of its atoms The atomic mass of an element is the weighted average of the mass of one mole of its atoms 1 mole of a compound = atomic mass of the compound 1 mole of a compound = atomic mass of the compound (Molar Mass)… (Molar Mass)… Mole Mass… Mass of one mole of compound Mole Mass… Mass of one mole of compound

15. What is a mole? For example, the relative atomic mass of carbon is 12, so one mole of carbon atoms weighs 12 grams. What is the mass of one mole of hydrogen atoms? The term mole is used to talk about mass. One mole of a substance is its relative atomic mass, or relative formula mass, in grams.

16. Molar Mass The atomic mass of an element or compound expressed in grams per mole The atomic mass of an element or compound expressed in grams per mole Atomic mass goes here CONVERSION FACTOR

17. Moles and Mass 1 mole of ______ has a molar mass of...... 1 mole of ______ has a molar mass of...... 2 grams of Hydrogen gas (H 2 ) = 1 mole of Hydrogen gas (H 2 ) 2 grams of Hydrogen gas (H 2 ) = 1 mole of Hydrogen gas (H 2 ) 16 g/mol17 g/mol 18 g/mol 36.5 g/mol2 g/mol

18. What is the mass of one mole?

19. Moles Beaker of Water Beaker of Water Mass of water is 18 g Mass of water is 18 g How many moles?? How many moles?? 1 mole 1 mole 1 mole H 2 O = 18 g 1 mole H 2 O = 18 g

20. Moles Beaker of HCl Beaker of HCl Mass of HCl is 36 g Mass of HCl is 36 g How many moles?? How many moles?? 1 mole 1 mole 1 mole HCl = 36 g 1 mole HCl = 36 g

21. 1 mole 18 g 1 mole 36 g

22. Amount vs. Weight Substanceamountunitsweight Apples 1 dozen 12 555 grams Donuts 1 dozen 12 250 grams Feathers 1 dozen 12 5 grams Bricks 1 dozen 12 10,000 g What do all these substances have in common?? Amount…… 1 dozen or 12 units Conversion factor????????? What is different about all these substances??? The weight….

23. Moles Beaker of Water Beaker of Water Mass of water is 36 g Mass of water is 36 g How many moles?? How many moles?? 2 moles 2 moles

24. CST Questions How many moles of carbon -12 are contained exactly 6 grams of carbon -12 How many moles of carbon -12 are contained exactly 6 grams of carbon -12 1. 0.5 moles 2. 2.0 moles 3. 3.0 moles 4. 16.0 moles 1. What is the Molecular mass? 12 g/mole 2. Convert grams into moles 6 g C x 12 g CH 4 1 mole CH 4 -----------------

25. CST Questions How many moles of CH 4 are contained in 96.0 grams of CH 4 ? How many moles of CH 4 are contained in 96.0 grams of CH 4 ? 1. 3.00 moles 2. 6.00 moles 3. 12.0 moles 4. 16.0 moles 1. What is the Molecular mass? 16 g/mole 2. Convert grams into moles 96.0 g CH 4 x 16 g CH 4 1 mole CH 4 -----------------

26. How many moles?