1. Chapter 2 Chemistry of Life

2. Atoms

5. (a) Electrons can be found anywhere in the cloud (b) Electrons are represented in orbit simply to show number

6. Where are those electrons??? Contrary to popular belief, electrons can be found anywhere in a cloud at any moment. Electrons are NOT in a predictable orbit around the nucleus!!

7. Element Substance made of only one type of atom Elements can be naturally occurring or man-made New elements are discovered every year; however, they do not last long enough to be significant

8. Periodic Table of Elements

9. C Chemical Symbol Carbon Chemical Name 6 Atomic Number 12.01 Atomic Mass

10. Ions Atom with a positive or negative charge Positively charged = more protons than electrons; occurs when atoms lose electrons (cation) Negatively charged = more electrons than protons; occurs when atoms gain electrons (anion)

11. Isotopes Atoms with different number of neutrons than typical atoms of the same element Example: –Carbon typically has 6 protons and 6 neutrons giving it an atomic mass of 12 –An isotope of carbon has 6 protons and 7 neutrons giving it an atomic mass of 13 –A radioisotope of carbon has 6 protons and 8 neutrons giving it a mass of 14

12. Isotopes of Hydrogen

13. How Isotopes Are Used Tracers/Markers –Able to label molecules with isotopes from other molecules because isotopes have different mass –Using mass spectrometer, can detect where certain elements go during a chemical reaction Radiometric (radiocarbon) Dating –Radioactive isotopes (Carbon-14) decays at a steady rate; therefore, they use that to calculate age of fossils and other artifacts.

14. Combining Chemical Symbols

15. Chemical Bonds Covalent Bond Ionic Bond Van der Waals Forces

17. Types of Covalent Bonds

18. More Covalent Bonds

20. Formation of an Ionic Bond

22. Van der Waals Forces Weak attraction between atoms and molecules due to unequal distribution of electrons Causes regions of an atom to have temporary charges (both positive and negative) Weakest of chemical bonds

23. Van der Waals and Geckos

25. Figure 2: Structural hierarchy of the gecko adhesive system. A. Ventral view of a tokay gecko (Gekko gecko). B. Foot of a tokay gecko, showing a mesoscale array of seta-bearing scansors (adhesive lamellae). C. Array of setae on the ventral surface of each scansor. D. Single gecko seta. E. Nanoscale array of hundreds of spatular tips of a single gecko seta. F. Synthetic spatulae fabricated in the lab of Ronald Fearing using nanomolding.

27. Application of Van der Waals & the Gecko http://scienceguy288.wordpress.com/2008/03/26/biomimetics-and-the-future-of-engineering/

28. Gecko Tape http://www.hero.ac.uk/uk/business/archives/2003/sticking_with_gecko_glue5188.cfm Using nanotechnology to make tape without chemical adhesives... Nanoengineering creates adhesive 200x more effective than gecko’s feet Spiderman toy with gecko tape on the palms... could develop to hold people as well as toys!!!