exam 1 Flashcards
density
mass divided by volume
1kg
1000g
1m
1000mm
temperature
how hot/cold something is
heat
the energy that flows from the object with a higher temperature to the one with a lower temperature
sig fig rules
- non zeros are significant
- leading zeros are NOT significant
- trailing zeros are significant when there is a decimal present
precision
how close the value are to eachother
accuracy
how close the values are to the actual value
protons
in the nucleus (positive charge)
nuetrons
in the nucleus (neutral charge)
electrons
surround the nucleus (negative charge)
why are atoms neutrally charged
because the number of protons and the number of electrons cancel each-other out
atomic #
the number of protons in the nucleus
isotopes
the same element with varied amounts of neutrons and thus a different mass #
atomic mass
the average of its isotopic weights
elements in the same _______ share similar behavior
group
transferring e-
ionic bond
sharing e-
covelant bond
positively charged ion
cation
negatively charged ion
anion
bonding
metals lose electrons — nonmetals gain
mass of an element to moles of an element
divide by the molar mass (on periodic table)
mol of element to molecules/atoms
divide by avagadros #
the assumed amount of product based on a chemical equation
theoretical yield
percent yield
actual divided by theoretical yield x 100
radioactivity
the spontaneous disintegration of a nucleus by the emission of radiation
nuclear reactions
atoms of one element are converted to atoms of another
large change in energy and mass
chemical reactions
atoms DONT change identity
small changes in energy/ no change in mass
alpha decay
4-2-He 2+
make heavy nucleus stable
utilized by EVERY element with molar mass over 83
beta decay
0/-1 B high speed electrons
proton emission: proton converts to nuetron and positron ( 0/1 B)
electron capture: draws in an electron
(0/-1 e)
gamma decay
have no mass or charge, accompany other types of decay, high energy photons
determining types of decay
nuetron rich: B- decay
proton rich: B+ decay
heavy: alpha decay
ionization
atom experiences ionizing radiation to form an ion+ and an e-
fission
heavy nucleus splits into two lighter nuclei
fusion
two lighter nuclei form a heavy one
nuclear binding energy
e every required to break 1 mol of a nuclei into individual nucleons
kinetic energy
motion
potential energy
position
internal energy (E)
kinetic + potential energy
energy in a system…..
must be accompanied by an EQUAL and OPPOSITE change in its surroundings
ΔE
transfer of energy from system to surroundings
heat (q)
thermal energy: transfer of heat to the lower temp
hot coffee cup ——-> cold air
work (w)
all other forms of energy transfer
ex. kicking a soccer ball
energy transferred out of a system is…
NEGATIVE
energy transferred into a system
POSITIVE
energy transferred through work
system RELEASE energy: work is done BY it
system ABSORB energy: work is done TO it
law of conservation of energy
ΔE overall = ΔE system + ΔE surroundings=0
internal energy
state function: depends on the current state of the system
pressure volume work
W = -P ΔV
expansion
losing energy by increasing volume
contraction
gaining energy by decreasing volume
specific heat capacity
the quantity of heat absorbed/released is proportional to its temperature change
calorimetry equation
q = c x mass x ΔT
magnitude of a thermochemistry exam equation is…
proportional to the amount of substance
rank the types of radiation in order of penetrating ability
alpha beta gamma (highest)
