FINALS! Flashcards
(119 cards)
homogeneous
same properties throughout
heterogeneous
different properties in different parts of mixture
elements
cannot be broken down chemically into simpler substance
compounds
can be broken down chemically into elements
precision
degree of agreement among several measurements of the same quality
accuracy
the agreement of a particular value with the true value
sigfig zero rules
- non-zero always count as sigfigs
a) leading 0s never count
2) captive 0s always count
3) trailing 0s only included if theres decimal points
density formula
mass/volume
atomic number
protons/electrons
atomic mass
protons + neutrons
ground state orbitals
lowest energy level/orbital
can be moved up by heat, electricity, light (excited)
quantum mechanics
how small particles behave
energy levels
measures fixed energy e-
since e- cannot exist between rungs, a quantum is the exact energy needed to move an e- up a rung
principal quantum number
denotes the energy level e- is located in
max in an energy level: 2n^2
aufbau
electrons enter the lowest energy level first
pauli exclusion
2 electrons max per orbital
hund’s rule
electrons don’t pair up unless they have to
alkali metals
group 1
most reactive
not found in nature
reacts with air and water
alkaline earth metals
group 2
reactive, but not as much as alkali
transition metals
group 3-12
all metals
least reactive on periodic table
found in nature
rare earth metals
bottom 2 rows
lanthanides
1st bottom row on periodic table
soft metals, not that rare
actinides
2nd bottom ro won periodic table
radioactive, synthetic
halogens
group 17
most reactive nonmetals