Terms Flashcards
What is the atomic theory?
- each element is composed of particles called atoms
- all atoms of a given element have the same mass and properties that distinguish them from atoms of other elements
- atoms combine to form compounds
- atoms of one element cannot change into atoms of another element
theory
a well tested explanation of why something happens; WHY
observations
what you see happens and some physical measurement you can make.
law
a concise summary of a large number of observations or experiments; can predict what will happen, but a theory is needed to explain why it happened; WHAT
examples of crystalline and amorphous solids
crystalline: arranged molecules like salt and diamonds
amorphous: do not have a well-ordered geometric shape like glass or plastic
accuracy
how close the measured value is to the actual value
precision
how close a series of measurements are to one another or how reproducible they are
systematic error
part of the experiment, predictable, occurs each time you measure. (unreliable scales off a few grams)
random error
external source causes problems, no way of predicting, will only occur sometimes (cloud goes over sun and lowers room temp.)
Law of Definite Proportions
all compounds, regardless of their sources or how they were prepared, have the same proportions of their constituents
nuclear theory
- most of the atom’s mass and positive charges are in the nucleus
- most of the volume is empty space where electrons are dispersed
- electrons and protons are equal so that the atom is electrically neutral
an element’s molar mass is numerically equal to…..
the elements atomic mass units (amu)
ionic bond
metal + nonmetal
covalent/molecular bond
nonmetal + nonmetal
acids
behind with H+
percent yield
actual/theoretical
percent composition
mass of element “x” in one mole of compound/ mass of 1 mole of the compound
Boyle’s Law
p1v1=p2v2
Charle’s Law
v1/t1=v2/t2
Avogadro’s Law
v1/n1=v2/n2
ideal vs. real gas
- real gases do not behave like ideal gases at high P or low T.
- ideal gas law assume no attraction between gas molecules ands gas molecules do not take up space (not valid at low T and/or high P
kinetic molecular theory
- the size of a particle is very small
- the average kinetic energy of a particle is proportional to the temperature (in K)
- all collisions are elastic
energy
the capacity to do work
work
the result of a force acting through a distance
1st Law of Thermodynamics
- energy cannot be created or destroyed
- total energy of the universe is constant
Energy is transferred only by….
work (w) or heat (q)
pressure= ______/________
force/area
barometer
uses height of a liquid to measure the barometric pressure
amplitude
measure of wave intensity
wavelength
wavelength or frequency of light waves determines its colour
photons
the energy of the particles of light
n (quantum mechanics)
principal quantum number
-main energy level (shell)
l (quantum mechanics)
angular momentum quantum number
-gives info on shape (s,p,d,f)
ml (quantum mechanics)
magnetic quantum number
-specifies orientation of orbital
Aufbau Principle
orbitals in the same sub shell have the same energy (degenerate)
-place one e- in each before completing pairs
Hund’s Rule
2 e- in separate orbitals will have lower energy than 2 e- in the same orbital b/c of decreased e- to e- repulsion
Pauli Exclusion Principle
no more than 2 e- per orbital
paramagnetism
has unpaired e- and will have a net magnetic field
diamagnetism
had only paired e- and will have no magnetic field
Non-Polar Covalent
- electrons shared equally
- 0-0.4
Polar Covalent
- electrons shared unequally
- 0.4-2.0
Ionic Bond
- electrons transferred
- 2.0-3.3
The _______ the __________________ the higher the vapour pressure.
-weaker, intermolecular forces
As temperature increases, the vapour pressure ____________.
increases
vaporization is….
endothermic
condensation is…..
exothermic
