General Chemistry

### Themes in bio

* Evolution: Living organisms are modified descendants of common ancestors and leads to unity/diversity of organisms
* Emergence: come out from whole; whole > parts
* Levels of organization is hierarchy


* Methods of investigating bio: scientific method
* Hypothesis: testable explanation for observations based on available evidence (can be falsifiable)
* Prediction: expectations from testing hypothesis
* Theory: broad explanation with significant support
* Law: statement of what always occurs under certain circumstances
* Observation -> background -> hypothesis -> prediction -> experiment -> evaluate (ask new questions, repeat/verify experiments, revise predictions)

### Basic chemistry

* Electrons: 25 of 92 elements essential to life; -1 charge; move rapidly; determine how atom interacts
* The further they are from the nucleus, the greater potential energy (usefulness) they have.
* When they are excited, they have a lot of potential energy that can be used to do work (such as how photons are involved in producing ATP).


* E- shell has e- PE
* Valence shell: outermost shell where bonds between e- form


* Part of atom (subatomic: proton, neutron, electron)
* Formation of molecules
* Chemical bonds: how atoms share e-; used to drive changes in bio. mol. -> energy -> change (energy is capacity to cause change)
* Molecules: compounds with 2+ atoms like H2O
* Emergent properties: compounds have different prop. Than elements (Na+ and Cl- -> NaCl)


* Chemical bonds
* Electronegativity: affinity for e- (atom attracting e- like O2); bond determined by difference; desire to fill valence
* Covalent: sharing e- (