Studied by 4 peopleformula for percent error
|measured - accepted| / accepted x 100 = percent error
why would the graduated cylinder be a better tool to measure 43.8 mL of liquid
the graduations are closer together letting you have a more precise answer. The more graduations, means more significant figures
what does an Erlenmeyer flask look like. Function?
sloped sides. used for holding and mixing liquids
what are significant figures
all the certain digits and one uncertain digit
units and tool to measure mass
grams; electronic balance
units and tools to measure length
feet; ruler
units and tools to measure temperature
degrees C and a thermometer
precise vs accurate
precise is how specific you can make an answer vs accurate is how correct the answer is
Bohr contributions and experiments
emission spectra of various elements to conclude that the electrons go around the nucleus in circular orbits
Rutherford contributions and experiments
shot alpha particles at a gold sheet; concluded that there is a dense positively charged nucleus with empty place
Thomson contributions and experiments
cathode ray; concluded that there is a subatomic particle called the electron
who created the periodic table of elements and how was it organized
Dimitri Mendeleev organized it by atomic mass and common characteristics
group 1
alkali metals
group 2
alkaline earth metals
groups 3-12
transitions
group 17
halogens
group 18
noble gases
same groups have what in common
same # valence electrons and common characteristics
same periods have in common
valence electrons are on the same principle energy level
3 subatonic particles and their mass, charge, and location
proton- 1.0073 amu; +; nucleus
neutron- 1.0087 amu; 0; nucleus
electron- 5.5 x 10^-4 or 1/2000 of a proton
nuclear notation
mass # (protons and neutrons)/ atomic # (protons) then followed by element
difference between isotopes
they have a different number of neutrons. radioactive isotopes have the wrong number of neutrons that make the nucleus unstable
how does an element become stable ( low potenial energy level )
it fulfills the octet rule and fills its outer shell with a full set of valence electrons
covalent compound characteristics
low melting point, poor conductor of electricity
metallic bond characteristics
ductile, good conductor of electricity, malleable
ionic compound characteristics
high melting point, dissolves in water
relationship between the strength of an intermolecular force and it's melting point
high melting point = stronger bond
6 ways to identify a chemical change
gas; color; light; temperature; precipitate; odor
energy released or absorbed when bonds are broken?
absorbed
energy released or absorbed when bonds are formed
released
when the enthalpy of reaction is negative, what type of reaction would it be
exothermic because more energy was released when forming bond than energy absorbed to break the bond
how many electrons are shared in a double bond
4 electrons
molar mass
the mass in grams of 1 mol of a substance
to find the mass of a certain amount of mol of a substance (equation)
amount of mole x molar mass (4.66 mol x 52.03g= 242.46 g/mol)
from mol to particle (equation)
1mole/molar mass x 6.022x10^23 (1 mol/52.03g x 6.022x10^23= g/mol)
Intermolecular vs Intramolecular
intermolecular- between molecules
intramolecular- within the molecules and between atoms
change in energy in photosynthesis
light (sun) >>> chemical potential energy
change in energy in cellular respiration
chemical potential energy >>> kinetic, heat, and potential energy
change in energy in combustion of fossil fueled to move a car
chemical potential (fossil fuels)>>> heat and kinetic energy
fossil fuels vs nuclear power in generating electricity
fossil fuels- combustion; chemical reaction occurs; chemical change; produces greenhouse gases
nuclear power- nuclear fission; radioactive waste; no greenhouse gases; no chemical reaction
what is energy
the ability to do work
Law of Conservation of Energy
Energy cannot be created or destroyed
in photosynthesis what happens to the energy from the sun?
it is used to split the water molecule and stored as chemical potential energy
what are coefficients
numbers infront of the reactants and products used to balance equations. tell us the number of particles of the substance. can be interpreted as moles of particles or # of particles
difference between chemical and physical change
chemical- in the intramolecular bonds and forms a new product
physical- intermolecular and does not change chemical formula
what type of bond is the strongest (single, double, triple)
triple bonds
why do atoms form bonds
they form bonds to fill their outs shell and have a lower potential energy
which part of the atom participates in chemical bonding
valence electrons
chemical equation fro photosynthesis
6H2O+ 6CO2 >>>C6H12O6+ 6O2
is photosynthesis exothermic or endothermic
endothermic
difference between nonpolar and polar covalent bonds
nonpolar covalent is balanced and polar covalent is not. their difference in their electronegativity
metallic bond
sharing of delocalized electrons
three properties of metals
malleability, ductility, and conductivity
what is electronegativity
indicates relative ability of an atom to attract electrons in a chemical bond
what is the general structure of the atom
positive dense nucleus that contains neutrons and protons, empty space, orbitals that contain electrons
atomic number
number of protons identifies element
atomic mass
number of protons + neutrons
the average atomic is the
weighted average
metals and nonmetals form
ionic bonds
metals are likely to form (ion)
cation
nonmetals are likely to form (ion)
anion
difference between a nuclear and chemical change
chemical- happens with the valence electrons and form a new substance
nuclear- nucleus changes, element changes
what is half-life
the amount of time it takes for half of the radioactive isotope to decay
what part of the nuclear power plant controls the rate of fission and absorbs extra neutrons
control rod
what part of the nuclear power plant contains fissionable uranium material
reactor core
what part of the nuclear power plant turns mechanical force into electricity
generator
what part of the nuclear power plant spins when pushed by steam
turbine
democritus conclusion
matter is made of an indestructible particle called an atom
john dalton contributions
atomic theory
atomic theory
-everything is made of an indestructible part called an atom
-elements have the same atom
-atoms don't get destroyed or created in a chemical reaction
-combine together to make compounds
what was Thomson's model of the atom called
plum pudding
quantum mechanical model
atom is a wave, electrons are in orbitals, different sizes ans shapes for the orbitals
in the quantum mechanical theory, as the principle energy level get bigger...
-oribtals gets larger
-electrons spends more time away from the nucleus
-electrons are less tightly bound to the nucleus
three types of nuclear reactions
radioactive decay; nuclear fission; nuclear fusion
radioactive decay
an unstable nucleus decays or emits a particle
nuclear fission
an unstable nucleus breaks up into smaller parts when hit with a nucleus
nuclear fusion
small nuclei combine to form a bigger nucleus
radiation
energy and particles that are emitted by radioactive atoms
types of radiation
-x rays - energy
gamma rays - energy
alpha particles - particles, have mass
beta particles - particles, have mass
nuclear energy
energy released from nuclear reactions
when do nuclear reactions occur
when the nuclei of atoms is changed through a reaction
where is nuclear energy stored
inside the atom, instead of in the bonds
isotopes
atoms of the same element with different number of neutrons
atoms
the basic unit of matter
why was Dimirti Mendeleev's periodic table unique
he was able to predict the properties of unkown elements
how is the modern periodic table organized by
atomic number, electron configuration, and recurring properties
electron configuration
arrangement of electrons in an atom
what does the electron dot diagram show
show the element with its valence electrons
octet rule
atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons
chemical formula
tells us the number of atoms each element that are bonded to make a compound
ionic bond is made up of
cation and anion
how is an ionic compound held together
electrostatic force (opposites attract)
what does bonding do the the atom (energy)
lowers the potential energy of the atom
cations are ( + or -) ions
postitive
anions are ( + or -) ions
negative
types of energy
chemical potential energy
light energy
sound energy
electrical energy
mechanical energy
what is the sun powered by
fusion of hydrogen atoms
what is a mole
a mole is a unit used to measure the amount of atoms, molecules, ions etc.
avogadros number
6.022 x 10 ^23
king henry died by drinking chocolate milk
king - kilo
henry - hecto
died - deka
by - base
drinking - deci
chocolate - centi
milk - milli
Note
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