LIFESCI 2 Lecture Notes - Lecture 1: Chemical Energy, Ionic Bonding, Chemical Formula
Document Summary
Electronegativity difference is high, becomes ionic bond, where electron from less electronegative is stolen. Chemical reactions: atoms keep their identity but change their chemical bonds. Chemical reactions 1) build and break down molecules for use 2) harness energy, which is stored in chemical bonds. Water molecules in their liquid form are more close, and in ice, are more spread apart, forming a lattice structure: thus, liquid water is more dense than ice. Hydrophilic: polar, and dissolve in water, making water a good solvent. Hydrophobic: nonpolar, avoid water; hydrophobic effect: polars exclude nonpolars. Because there are hydrogen bonds, the energy from heating, rather than increasing molecular motion and thus an increase in thermal energy, the energy is used to break hydrogen bonds, thus making water resistant to heating (high heat capacity) Ph= -log[h+] acid has higher concentration of h+ than oh-, thus it is a molecule that releases a proton (h+) a base accepts the proton (h+)
