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Chemistry of Life

Chemistry of Life. The basics of Chemistry. Matter is recycled and rearranged for living organisms. Living matter is made up of different substances. Example of substances: pure CO 2 , glucose, pure salt, H 2 O…. CO 2. glucose.

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Chemistry of Life

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  1. Chemistry of Life

  2. The basics of Chemistry

  3. Matter is recycled and rearranged for living organisms • Living matter is made up of different substances. • Example of substances: pure CO2, glucose, pure salt, H2O….. CO2 glucose

  4. Atoms - Smallest unit of an element (with properties of that element) • Nucleus-dense center containing: • Protons- positively charged particles • Neutrons- particles with no charge • Electrons (e-) - small, negatively charged particlesthat orbit nucleus in clouds or shells (2, 8, 8) • Valence e-- found in outermost energy level How many total e-? How many valence e-? What element?

  5. A=P=E M=A+N Atomic number = Proton number = Electron number Mass = Atomic Number + Neutrons

  6. Click on image to play video.

  7. Check for Understanding • How would an element’s identity change if you took away or added protons?

  8. The 17 essential elements in plants (autotrophs)… CHOPKINS Ca Fe Mg B Mn Cu Zn Mo Cl Carbon, Hydrogen, Oxygen, Phosphorous, Potassium, Iodine, Nitrogen, Sulfur, Calcium, Iron, Magnesium, Boron, Manganese, Copper, Zinc, Molybdenum, Chlorine C HOPKINS Café Managed by my cousin Mo Cline

  9. 96% of living matter: C, H , O, and N • 4% of living matter: Ca, K, P, S, Na, Cl, Mg, Fe, and trace elements

  10. Check for Understanding Hypothesize as to why these elements are near the top of the periodic table. (answer in the left margin)

  11. Atoms, Molecules and Compounds

  12. Molecules and Compounds • Molecule- 2 or more elements joined together by chemical bonds • smallest unit of a compound

  13. Check for Understanding • What is the name of the compound in the bottle? • What is the molecular formula? • What is the structural formula? • How many molecules of the substance are in the bottle? • How would you calculate this?

  14. Chemical reactions 6CO2 + 6H2O  C6H12O6 + 6O2 • Lead to changes in substance or matter. • Occurs when electrons are transferred between two atoms (lost, gained or shared)

  15. Octet Rule • The octet rule is a chemical rule that states that atoms with atomic number <20 tend to combine in such a way that they each have eight electrons in their valence shells. • 1st Shell holds up to 2 electrons max • 2ndShell holds up to 8 electrons • 3rdShell holds up to 8 electrons as well • An Oxygen atom diagram

  16. Practice • Al • Mg • S • Ne • N • Draw the atoms for the elements listed at the left and show the protons, neutrons and electrons. Under the drawing write a sentence telling me how many valence electrons there are.

  17. Drawing Atoms • As scientists, we want to be efficient • Instead of drawing all of the electron shells, we only need to draw the valence electrons • A Lewis Dot diagram will make drawing molecules and compounds easier

  18. Lewis Dot Diagrams • The inner shells are not involved in bonding • Carbon is in group 14, so that means 4 valence electrons • We often write the element symbol and only the valence electrons

  19. You try… What does the Lewis dot diagram look like for Oxygen? What does the Lewis dot diagram look like for Sodium? Hydrogen? How about Lithium? Why are they all the same? Na H Li

  20. Ions = electrically charged matter • Ions form when electrons are lost or gained. • Ionic bonds form when a positive ion is attracted to a negative ion.

  21. Making Salt…Lewis dot style (Ionic bond)positive Na+ attracted to negative Cl-

  22. Click on image to play video.

  23. Covalent bond = two atoms sharing electrons • “Strong” • Relatively stable • Hydrogen, oxygen, and nitrogen can readily form covalent bonds with carbon.

  24. Hydrogen Bonding • Weak bonds between a hydrogen of one molecule to an adjacent negative molecule • Ex: attraction between water molecules.

  25. Mixtures Physical combinations of substances • There are several types of mixtures: • solutions • suspensions • Colloids, or colloidal dispersions

  26. Mixtures Physical combinations of substances Air = solution Cytoplasm = colloid Kool-Aid= solution Jello = colloid Blood = suspension

  27. Check for Understanding Name 3 solutions found in every day life. Can you think of a suspension? How about a colloidal dispersion?

  28. Exit Ticket • Put your FULL NAME, Date and Period on the BACK side. • Divide the ½ sheet provided into 3rds.

  29. In the first box, diagram an atom of Hydrogen and show the protons, neutrons and electrons including the valence electrons • In the second box, diagram an atom of Carbon and show the protons, neutrons and electrons including the valence electrons • In the third box, diagram an atom of Oxygen and show the protons, neutrons and electrons including the valence electrons

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