1. a single chemical compound or element that is found in nature amorphous 2. the amount of kinetic energy that a material can absorb without breaking cleavage 3. a break that does not follow a flat surface, but rather is rough and uneven crystal 4. resistance to being scratched fracture 5. a solid form resulting from the arrangement of atoms, ions, or molecules in definite geometric patterns hardness 6. a clean break parallel to planes of weakness in a crystal mineral 7. a non-crystalline solid having no orderly arrangement of molecules toughness

You mix the pks of succinic acid are 4.21 and 5.64. how many gramsa graduate student at sdsu wants to measure the activity of a particular enzyme at ph 4.0. to buffer her reaction, she will use a buffer system based on one of the acids listed below, which acid is most appropriate for the experiment? of monosodium succinate (fw = 140 g/mol) and disodium succinate (fw = 162 g/mol) must be added to 1 l of water to produce a solution with a ph 5.28 and a total solute concentration of 100 mm? (assume the total volume remains 1 liter, answer in grams monosodium succinate, grams disodium succinate, respectively.) volumes of 0.05 m nah2po4 and 0.05 m na2hpo4 (pk's for phosphoric acid are 2.15, 6.82 and 12.38). which of the following best describes the resulting solution?

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.