AP chem unit 1

compounds can be separated into elements by

chemical changes

mixtures can be separated by

physical changes

filtering separates mixtures based on

differences in particle size (large particles are trapped on filter paper while the soluble component goes through the filter paper and stays in the "filtrate"

distillation separates mixtures based on

differences in boiling point

chromatography separates mixtures based on

differences in polarity

in paper chromatography, the component that is the most similar in polarity to the "mobile phase" moves up

the farthest

mass is conserved during

chemical and physical changes

when reading a volume of a liquid in a container, you can estimate by

reading in between the graduated markings, which gives you one more sig fig in your volume

ranking measuring devices from least precise to most precise

beaker, graduated cylinder, volumetric flasks, burette

density=

mass/volume

the % composition by mass for a pure compound

does not change

when an electron is in a higher energy level, it is

farther away from the nucleus, and therefore has less Coulombic attraction to the nucleus and is therefore easier to remove (it has a lower first ionization energy)

Moving across a row on the periodic table

the effective nuclear charge increases, therefore the valence electrons are more attracted to the nucleus, therefore the atomic radius decreases and the ionization energy increases

When reading a PES graph, the higher the peak

the more electrons there are in that sublevel

a larger binding energy means

that the electrons are closer to the nucleus

when writing the electron configuration for a cation

remove the valence electrons first (p-orbital and s-orbital, then d-orbital if necessary)

isotopes of an element have

the same number of protons, but different numbers of neutrons

mass spectroscopy graphs measure

atomic masses of isotopes

elements in the same group (vertical columns) have

similar chemical and physical properties

metals are on the

left side of the zig-zag line

nonmetals are on the

right side of the zig-zag line

cations (+) are

smaller than their atoms since you are removing valence electrons that are farther from the nucleus

anions (-) are

larger than their atoms since adding extra electrons increases electron-electron repulsions