midterm review Flashcards
Explain why a fluorescent rock glows when uv light hits it.
an electron in the fluorescent rock absorbs the uv light causing the electron to gain potential energy and jump into a higher energy level. Then, naturally, the electron relaxes back down to a lower potential energy level because it is coulombically attracted to the positive nucleus. this causes a photon of light to be emitted
who discovered the electron
JJ Thompson
how was the electron discovered
JJ Thompson discovered the atom using a cathode ray tube
what experiment did Ernest Rutherford do
sent alpha particles through a gold foil, some deflected and some went through
what did Rutherford discover
that the atom had a tiny, dense nucleus at the center of every atom which consisted of almost all of the mass and all of the positive charge of the atom
what Greek philosopher came up with the atom
Democrites
two balloons have the same volume at the same temp and pressure but contain different gasses. What quantities of the two balloons must be the same
the density, the moles
how to find molar mass of a molecule
add the molar mass of each element
how to find how many atoms of an element are in a compound
find the number of small particles in the molecule and the element, then do part over whole
how to convert moles to mass
use the periodic table molar mass
how to convert moles to gas at stp
1 mol = 22.4 mL
how to convert moles into small particles
6.02x10^23
