Interrelated Scientific Principles
Matter, Energy and Environment
Part 2: Matter & Energy
1. Atoms
- Fundamental subunits of matter
- 92 naturally occurring
- Elements are made of specific atoms
- Central region = nucleus
- Protons (+ charge)
- Netrons (0 charge)
- Surrounding cloud: fast moving, electrons (- charge)
2. Diagram of the Oxygen Atom
3. Periodic Table of the Elements: Search the web for a Periodic
Table.
4. Isotopes: atoms of the same element that differ from one
another in the number of protons, neutrons and electrons present. (See
Figure 4.5 in Text)
5. Compound
- Definition: 2 or more atoms or ions bonded chemically
- Example:
- Water: H2O or HOH
- See Figure 4.7, Text
6. Some compounds are large and complex, with multiple atoms of
different elements (Surf the web for different representations of
Sugar: C6H12O6. Be sure to notice that although the Netscape
composer program doesn't put in superscripts and subscripts, that they
are normally put in for chemical formulas.)
7. Some biomolecules are made of several large subunits
- These two graphics represent the 4 subunit molecule hemoglobin
which is responsible for transport of oxygen and carbon dioxide in your
blood stream. (Surf the web for graphic representations of hemoglobin)
8. Mixtures are variable combinations of atoms, ions or molecules.
Examples
- Honey: sugars and water
- Concrete: cement, sand, gravel and reinforcing rods
- Cake: sugar, flour (a mix of proteins, carbohydrates, fats),
butter (a mixture of different fats), water, milk& eggs (both very
complex mixtures of proteins, carbohydrates, fats and nucleic acids).
9. Review (see Table 4.2, text)
10. pH
- Definition: negative log of the hydrogen ion concentration.
- Hydrogen ions are protons, they have a positive charge.
- Acids
- any compound that releases protons in solution
- Examples: sulfuric acid (H2SO4), vinegar (HCH2COOH)
- Bases
- Any compound that accepts hydrogen ions in solution
- Examples: ammonium hydroxide (NH4OH), lye or sodium hydroxide
(NaOH)
11. pH scale (See Figure 4.6 in Text)
- neutral: 7
- acid: below 7
- base: above 7
12. Chemical Reactions
- Atoms of compounds are held together by chemical bonds
- Chemical bonds - attractive forces between atoms resulting
from the interaction of their electrons
- Exothermic reactions: energy released when new bonds made
- Endothermic reactions: energy added to make new bonds
13. Burning methane: a chemical reaction (See Figure 4.8,
Text)
14. Chemical reactions in living things
- Living organisms have chemical reactions that take place at
relatively low temperatures
- Enzymes (proteins) allow the reactions of life to take place at
these lower temperatures by lowering the energy needed to make and
break bonds.
15. Metabolism
- Photosynthesis
- Sunlight energy + 6CO2 + 6 H2O -------> C6H12O6
- Respiration
- C6H12O6 ------> 6CO2 + 6 H2O+ Energy
16. The process of Photosynthesis: Figure 4.9.
17. The process of Respiration: Figure4.10
18. Energy
- Energy: the ability to do work.
- Work: an object moved over a distance.
- Kinetic: energy of movement
- Potential: energy of position
19. States of Matter (Figure 4.12).
20. Thermodynamics
- 1st law: energy can neither be created nor destroyed, only
changed from 1 form to another.
- 2nd law: when energy is converted from one form to another,
some of the useful energy is lost to the system --> entropy
21. Environmental Implications of Energy Flow
- Organisms produce heat - lost to the environment
- Machines produce heat when working.
- On your own: Why are some forms of energy of higher “quality”
than others?
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