October 4th
Corrections to story about Bose-Einstein Condensates.
Virtual particles?
Dynamic periodic table: kinda cool, or at least I think so...
Virtual particles?
Dynamic periodic table: kinda cool, or at least I think so...
Review: Ionic compounds
Remember: hydrogen is not a metal!
Molecular compounds
* Electronegativity: "a measure of the ability of a specified atom to attract electrons". If you'll allow me to get anthropomorphic**, electronegativity is how much an atom wants to get one more electron: fluorine really, really, really wants it, carbon could take one or leave one without caring greatly which, and lithium absolutely does not want another electron: in fact, lithium would rather get rid of the one outer-shell electron it already has.
** Anthropomorphic: describing non-human things as having human emotions, desires, drives, etc.
- Between metal and non-metal
- Essentially giving and taking electrons
- Chemical formula: shows ratios of elements, but not much about structure
- Structure is some sort of repeating lattice: examples here, and here, and here, and here
Remember: hydrogen is not a metal!
Molecular compounds
- Generally, compounds without metals
- Covalent bonding: because the atoms are not extremely different in electronegativity*, they share electrons rather than simply take or lose them
- Molecular formulas: show not just the ratios of elements, but also exactly how many atoms are in one molecule
- Structure is based on the molecule: a distinct assembly of atoms, with structure, specific connectivity, shape. The structure of a molecule is crucial to determining the properties of a compound: change the molecule in even just a minor way and you can have major effects on the properties of the compound.
* Electronegativity: "a measure of the ability of a specified atom to attract electrons". If you'll allow me to get anthropomorphic**, electronegativity is how much an atom wants to get one more electron: fluorine really, really, really wants it, carbon could take one or leave one without caring greatly which, and lithium absolutely does not want another electron: in fact, lithium would rather get rid of the one outer-shell electron it already has.
** Anthropomorphic: describing non-human things as having human emotions, desires, drives, etc.
Naming compounds
See section 4.4 in the book: that section says enough. I am not going to require that you know the names of the polyatomic ions.
See section 4.4 in the book: that section says enough. I am not going to require that you know the names of the polyatomic ions.