CHEM111 - Exam1 Flashcards
a concise verbal or mathematical statement of a reliable relationship between phenomena. for example finding a pattern or trend and summarizing the findings with a ____
law
unifying principle that explains a body of experimental observations and the laws that are based on them. they can als be used to predict relate phenomena, so these are always being tested. if it is disproved by an experiment, then it must be discarded or modified so that it becomes consistent with experimental observations
theory
composition is not uniform.
ex: sand with iron filling, egg white
heterogeneous
composition of mixture is uniform throughout
ex: sugar in water, cough syrup
homogeneous mixture
elements of the same type of atom
pure substance
when two elements are combined
ex: carbon dioxide
Compound
you can classify items as an element
ex: neon
can be observed and measured without changing IDENTITY of substance (solubility, conductivity, magnetism, density, boiling point, melting point)
- lead melting at very high temp
- condensation of water
- dilution of a juice concentrate
physical property
a chemical change or chemical process must occur. after change, original substance no longer exists
ex: iron rusts when exposed to H20 or air
chemical property
one in which the state of matter changes, but the identity of matter does not
ex: melting
physical change
the change, for example, corrosion or oxidation
chemical change/chemical process
numbers
quantitative
words (not measurements)
qualitative
does not depend on amount of matter; not additive
ex: density and temperature; adding two beakers of water will have same density and temperature
intensive property
measured value that depends on amount of matter; mass and length
ex: mass (more matter means more mass); adding two coins to have a combined mass
extensive property
*the mass of an atom in atomic mass units; atomic mass unit is equal o 1.6605378 x 10^-24g
average atomic mass/weight
total number of neutrons and protons present in the nucleus of an atom of an elemet
mass number
the number of protons in the nucleus of each atom of an element
atomic number
how close measured numbers are to one another
precision
how close measured numbers are to a true value
accuracy
atoms that have the same atomic number (Z) but different mass numbers (A)
isotopes
The scientific method gives rise to ____, data gives rise to ____, these are tested with experiments, and successful hypotheses give rise to ___, which are further tested by an experiment.
laws, hypotheses, theories
horizontal rows
periods
a good conductor of heat and electricity
metal
a poor conductor of heat and electricity
nonmetal
an element with properties that are intermediate between those of metals and nonmetals
metalloid
a vertical column of elements in the periodic table. referred to by group number ex 1A, 2A, etc
group
Group 1A
Alkali metals
Group 2A
Alkaline earth metals
group 6A
Chalogens
group 7A
Halogens
group 8A
Noble gases
group 1B and groups 3B-8B; These elements are very hard, with high melting points and boiling points
transition elements/metals
(has some of the lighter transition metals) are the most abundant elements on the earth, in the solar system, and in the universe. They are sometimes called the representative elements.
main group elements
A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.
electromagnetic radiation
the distance between identical points on successive waves (successive waves or troughs)
wavelength (lambda)
the number of waves that pass through a particular point in 1 second (v)
frequency
the vertical distance from the midline of a wave to the top of the peak or the bottom of the trough
amplitude
_____ ____ has an electric field component and a magnetic field component: have same wavelength, frequency, and amplitude, but vibrate into two mutually perpendicular planes
electromagnetic wave
Describe Bohr model of the atom an use it to explain the line emission spectra of hydrogen
an electron in bohr model: the electron absorbs energy and is promoted to an excited state, then the energy is lost and goes to ground state producing a photon of light and only certain quanta of energy are emitted with particular wavelength, frequency, and energy
when n=1, which corresponds to the most stable energy state; the lowest energy of an atom
ground state
each energy in which n > 1; higher in energy that the ground state
excited state
designates the size of the orbital (n)
principal quantum number
(l) describes the shape of the atomic orbital; the values of l are integers that depend on the value of the principal quantum number, n.
- values of l range from 0 to n - 1
GIVE VALUES
angular momentum quantum number
n=1 l=0
n=2 l=0,1
n=3 l=0,1,2
s subshell:
l=0
p subshell
l=1
d subshell
l=2
f subshelll
l=3
describes the orientation of the orbital in space (ml); within a subshell, the value of ml depends on the value of l
ex: 0 s subshell = 0, so one orbital
- 1 p subshell -1,0,1, so three orbitals
magnetic quantum number
(ms) to specify the electrons spin
electron spin quantum number
