Zoom into Air Large Scale 2 Air contains rain drops 1 cm Macro Scale 3 Air also contains water droplets Macro Scale 4 Single cloud droplet Micro Scale 5 When we zoom in even smaller…. H2O …. we still see water! Atomic-molecular Scale 6 Other Molecules in Air Oxygen O2 Water H2O Nitrogen Carbon dioxide N2 CO2 Atomic-molecular Scale 7 What’s in our atmosphere’s air? Nitrogen (78%) Oxygen (21%) Argon (0.9%) Carbon dioxide (0.03%) Water (variable) 8 What is the difference between an atom and a molecule? 1. 2. 3. Oxygen Carbon dioxide Argon 4. 5. 6. Nitrogen Oxygen Hydrogen 7. 8. 9. Carbon Nitrogen Water 9 Enter: “Chemical Change Notes” into your journal’s Table of Contents 10 Three Facts about Atoms 1. Atoms last forever (except in nuclear changes). 2. Atoms make up the mass of all materials. 3. Atoms are bonded to other atoms in molecules. 11 Two Questions about Chemical Change • A chemical change is: – A change in matter where atoms are rearranged into new molecules. • Scientists try to answer these questions about chemical changes that involve carbon atoms: – Location: Where are atoms moving? (Where are atoms starting? Where are they moving to?) – Carbon: What is happening to carbon atoms? (What molecules are the carbon atoms in before the chemical change? How are the atoms rearranged into new molecules?) 12 Class Data Chart Time (min.) Change in mass: Soda Water Our data Time (min.) Class Avg Change in mass: Regular Water Our data 0-5 0-5 5-10 5-10 10-15 10-15 Class Avg Soda Fizz Lab Graph Change in Mass 0.10 0.05 0.00 -0.05 -0.10 -0.15 5 10 Minutes 15 Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Chemical Change = A change in matter where atoms are rearranged into new molecules. Soda Water Fizzing Water Evaporating Soda water was undergoing a chemical change because…. What happens when soda water loses its fizz? Where are atoms moving from? Where are atoms moving to? Chemical change What molecules are carbon atoms in before the change? What other molecules are involved? What molecules are carbon atoms in after the change? What other molecules are involved? Remember: Atoms last forever (so you can rearrange atoms into new molecules, but can’t add or subtract atoms)