Semester 1 Final Flashcards
Matter has
substance, stuff, it is anything that has mass and volume
___is the property of matter that can be measured
mass
the amount of space matter takes up is called
volume
Mass is measured in
milligrams(mg), grams(g)(1000mg), and kilograms(kg)(1000mg)
Volume is measured in
milliliters(mL), and liters(L)(1000mL)
calculating the conversion of some units to another unit is
information given x conversion factor(s) = information sought
elements
building material of all matter, the purest form
compound
different elements combined in specific ratios, represented by a chemical formula
ratios of the elements in compounds __ change
never
ratio of carbon to oxygen atoms in CO2
1:2
molecules
multiple atoms of the same element combined, not compounds
Aqueous Phase
when a substance forms a mixture with water ex. seawater, vinegar. It is not a liquid
Homogenous Mixture
one phase, solution or pure substance ex. sugar + water
Heterogenous mixture
2 or more phases, can be separated by filtration or extraction ex. sand + water
Reactivity
property describing how easily an element will combine with other substance to form new compounds
the more reactive an element is,
the more rapidly it combines with other elements
Atomic Mass
mass of an atom, measured in atomic mass units(amu)
Periodic table
arranges the 118 chemical elements into rows and columns, based on a set of repeating properties
Vertical columns
called groups
horizontal rows
called periods
in chemistry, positive ions can be called
salts
the elements on the periodic table can be grouped into
metals, metalloids, and nonmetals
atom
the smallest particle of an element retaining its identity in a chemical reaction; made of subatomic particles
subatomic particles
protons, neutrons, and electrons
proton
subatomic particle with a positive charge equal to about 1 amu, p+
electron
subatomic particle with a negative charge equal to about 0.000055 amu, e-
neutron
subatomic particle with no charge equal to about 1 amu, n0
nucleus
dense central core of atoms made up of neutrons and protons - makes up most of an atom’s mass
electron cloud
electrons surrounding, orbiting, the nucleus - makes up most of an atom’s volume
atomic mass unit(amu)
unit used to measure the mass of subatomic particles
atomic number
number of protons in an atom, which determines the identity of an element
normal atoms have what charge and why
neutral because the number of protons and electrons is the same
Mass number
total number of protons and neutrons in an atom
Isotope
atom with the same number of protons but a different number of neutrons, therefore, different atomic numbers
to calculate average atomic mass of isotopes of an element
create weighted average, so use ratios as percentages that multiply amus and add together
(0.9)(20amu)+(0.09)(22amu)+(0.01)(21amu)= 20.19amu
transmutation
conversion of one element into an atom of another element, occurs naturally thru radioactive decay, when nuclei emit particles an rays
Nuclear Stability is controlled by two forces
electrostatic repulsion force and the strong nuclear force
electrostatic repulsion force
repels positively charged particles, so when protons in an atom increase, the force increases
strong nuclear force
short range force on atoms independent of charge, when overall number of subatomic particles in nucleus increases, force increases
the large an atom’s nucleus, the more the __ force overpowers the __ force
repulsion, strong
an imbalance in force in an nucleus creates
instability
Valley of stability
atoms with atomic numbers under 80
alpha decay
decay of an element to stabilize nucleus that involves the emission of an alpha particle, or the nucleus of a helium, 2 neutrons and 2 protons
alpha particle(4/2 He) emitted and atom changes
222/88 Ra –> 4/2 He + 218/80 Rn
quirks
make up neutrons and protons,
-up quirks
-down quirks
proton have 2 up quirks and 1 down quirk
neutron has 1 up quirk and 2 down quirks
beta decay B- (negative)
decay of an element to stabilize nucleus that involves the transformation of a neutron into a proton, creating a high energy electron
90/39Y – B- –> 90/40 Zr
In beta decay, the atomic number __ while the mass number __
changes, remains the same
beta decay B+ (positive)
decay of an element to stabilize nucleus that involves the transformation of a proton into a neutron, creating a positron(positive electron)
49/25 Mn –> 49/24 Cr + 0/+1 e
light is made up of
waves with varying wavelength
the shorter the wavelength of a light
the more energy it has
blue light has __ wavelengths while red light has __ wavelengths
longer, shorter
when heated, some electrons get “excited”, moving
father from the nucleus to the next orbit, but its instability causes it to fall to a lower energy state by emitting a photon of specific energy
an energy input causes electrons to move up to
excitation, followed by an energy output, leading to relaxation
electron shells
circles, orbits, or electrons around the nucleus
each electron shell represents a discrete
(specific) energy level
Atomic Emission Spectrum(AES)
pattern formed when light emitted by an element, unique to every element, because an atom in a gas state emits light when energy is absorbed
energy is quantized in energy input and output
only discrete, specific, values are allowed, the opposite is continuous values
an electron can change energy level to one higher only if
it absorbs the difference in energy levels
light not only acts like waves, also like
particles
Quanta
particles of energy, in quantum theory, the smallest amounts of energy in nature
an energy gap in electron shells gets continuously __ the farther away from nucleus
smaller
valence shell
outermost atomic shell, all the electrons in btwn nucleus and valence shell are called core electrons
valence electrons
electrons on outermost shell of an atom, which affect a chemical’s reactivity, as chemicals with the same number of valence electrons have similar properties
HONC Rule
hydrogen makes one bond, every oxygen makes two bonds, every nitrogen makes three bonds, every carbon makes four bonds. These are covalent
Isomers
molecules with different structural formula but same molecular formula. Have different chemical and physical properties
Because of 3D aspect of molecular structure, structural formulas show sequence in which atom is connected to next; can be rotated, as the __ and __ of connections are what matter
number, type
VSEPR(Valence Shell Electron Pair Repulsion) Theory
Tendency for electron pairs to be as far apart from one another as possible
Bond Rotation
p-orbital overlap in carbon-carbon single bond allows for axel rotation
conformation- structures differing only differing in rotations
double p-orbital overlap in a carbon-carbon results in fixed geometry, double bond can __, and single bond can’t
rotate
presence of double bond(two pairs of electrons shared) enables
cis/trans-isomerism
cis-symmetrical sides to atom in terms of non-hydrogen group
trans- non-hydrogen groups are diagonal
functional group
an atom or group of atoms within a molecule that has similar chemical properties whenever it appears in various compounds. Even if other parts of the molecule are quite different, certain functional groups tend to react in certain ways.
Structural (constitutional) isomers have the same molecular formula but ___. Stereoisomers have ___ molecular formulas and arrangements of atoms.
have a different bonding arrangement among the atoms
identical
where are electronegativity values the highest on the periodic table
where are they lowest
bottom right corner,
top left
difference in electronegativity in covalently bonded atoms determines
polarity, the larger the difference the more polar, because the atom with higher electronegativity will develop a partial negative charge relative to the other in bond, and single bonds with bigger difference lead to greater bond dipoles
differences in electronegativity
0-0.4 - nonpolar covalent
0.5-1.8 polar covalent
>1.8 Ionic Bond
dispersion forces are the result of electrostatic interactions that are merely __ and __, occuring in non-polar molecules
temporary and fluctuating
dipole dipole interactions
stronger than dispersion because molecules more polar
hydrogen bonding
strongest type of intermolecular interaction because H covalently bonded to N,O, and F and a dipole by electronegative atom(N,O,F) in a different molecule or a different part of the same molecule
intramolecular forces of attraction(ionic and covalent) are ____ than intermolecular forces of attraction
stronger
vapor pressure and boiling point are directly related to the strength of the
intermolecular interactions
P.S.
melting points also tend to correlate with interaction strength, but because the interactions are only rearranged, in melting, the relations are more subtle
ionic solids have __ vapor pressures, __ melting points, and __ boiling points
low, high, high,
they conduct electricity only when ions are mobile, as when the ionic solid is melted or dissolved in water
kelvin temperature of a sample of matter is directly proportional to the
average kinetic energy of the particles in the sample
density of a substance formula
p=m/v
density = mass/volume
volume is inversely proportional(when increases, density decreases)
mass is directly proportional(when increases, density increases)
ex. mg/mL, g/L, kg/m^3 = mg,g,kg / mL, L, cm^3, m^3
critical point on phase diagram
the point in temperature and pressure on a phase diagram where the liquid and gaseous phases of a substance merge together into a single phase. Beyond the temperature of the critical point, the merged single phase is known as a supercritical fluid .
triple point on phase diagram
3 phases coexist
chemical equilibrium
dynamic condition where the rate of forward reaction equals the rate of the reverse reaction
Kinetic molecular theory of Gasses(keep in mind these are laws in ideal conditions)
- Gasses are comprised of small molecules far apart from each other
- Collisions between gas molecules and the wall of the container are elastic, meaning that the molecules maintain speed and bounce
- Gas molecules are in constant random motion
- There is minimum/no attractive force between Gas molecules
- Temperature is directly proportional to Kinetic energy K.E.=1/2m(mass) x v(velocity)^2
gas pressure
caused by forces of collisions between molecules of gas and container walls. As the container is shrunk, the pressure and collisions increase.
gasses with higher temperature will have
faster particles –> more collisions –> higher pressure
opposite for lower temp
In Real Gasses there is/is not attractive force when compressed?
is, and kinetic energy is insufficient to overcome the attractive force
PSI is a unit used to measure __,
given by formula __
pressure,
pounds/inch^2
how do liquids behave in comparison to gasses
particles are in constant random motion just as gasses, however, particles are closer together because of intermolecular forces of attraction. liquid molecules are also less mobile, and there is less void space in between particles
Both liquids and gasses can diffuse
unlike gasses, fluids are/are not compressible?
are not, because fluid density is about 1000x of gas of same substance
liquid property of surface tension
liquids decrease surface area to smallest possible size, done by adjacently-pulling force on liquid surface. this property resists penetration
capillary action
attraction of the surface of a liquid to the surface of a solid
vaporization vs evaporation
vaporization any conversion from liquid to gas(including boiling or equilibrium), while evaporation does not include the liquid reaching its boiling point yet particles from liquid surface escape to atmosphere
Liquids with higher temperatures have a __ proportion of molecules of __ kinetic energy(enough to evaporate) in comparison to liquids with lower temperatures
higher
high
gas to liquid
gas to solid
liquid to solid
liquid to gas
solid to liquid
solid to gas
condensation
deposition
freezing
vaporization
melting
sublimation
boiling point
temperature at which equilibrium vapor pressure of the liquid equals the atmospheric pressure
dynamic gas liquid equilibrium
opposing changes occur at equal rates in a closed system, rate of evaporation equals rate of condensation
vapor pressure
pressure exerted by vapor in dynamic gas-liquid equilibrium with its corresponding liquid at a given temperature
more particles in the vapor phase causes a higher vapor pressure
intermolecular forces of attraction relation with vapor pressure
stronger IMFA equals lesser vapor pressure
volatile liquids
evaporate readily because of relatively weak intermolecular forces of attraction
altitude’s relationship with pressure
higher altitude has lower atmospheric pressure
at a substance’s melting point its particles
slide past each other
aufbau principle
electrons are filled into atomic orbitals in the increasing order of orbital energy level.
electron configuration notation
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p
s, p, d, and f sublevels/oribtial in energy level hold _ _ _ _ electrons
2, 6, 10, 14
formula for electrons is 2n²
sublevel n =
principle quantum number
Bohr electron model is ___ rather than probablistic, which is the
deterministic
electron cloud model
Atomic Emission Spectrum
an atom in the gas state emits light when energy is absorbed, pattern formed when light emitted by an element, unique to every element
noble gas shorthand
shorthand including a noble gas as filler for first energy sublevels filled since noble gasses stable with octet, use noble gas preceding element notated
polyatomic ion
pre-determined ionic compound, treated as an entity, and cannot be destroyed in most chemical reactions
what sort of element written first in ionic compound
metal
in ionic compounds the anion ends with the suffix
ide
ionic bond
extremely stable electrostatic attraction holding oppositely charged ions
ionic compound
ex. NaCl, Sodium Chloride
ionic bonds form between metal and nonmetal reacting to make electrically neutral compound made of cations and ions that balance charges
electrolytes
ionic compounds dissolved in water that which makes aqueous solution conductive
covalent bonding
only in non-metals when atoms share pairs of electrons
metallic bonding
metals lose electrons to form positive ions and delocalised electrons, bond is strong electrostatic attractions between cations and delocalised electrons from valence shells of metal ions, array of positive metal ions surrounded by sea of electrons
molecular solids have low melting point because
covalent bonds exist in the molecules but between them there is low imfas,
molecular solids don’t conduct electricity because
the valence electrons are held tightly between the covalent bonds and the lone pairs of each molecule
metallic solids are good conductors of heat and electricity because
of delocalised electrons,
Avogadro’s Number
6.022x10^23, describes the number of particles or formula units in a mol of a pure sample of a substance
chemical reaction
when a substance is transformed into a new substance, typically with a different composition. In this process heat, light, formation of a gas, formation of a precipitate, and/or a color change indicate that a chemical change has occured.
chemical reactions can be categorized into five types
synthesis, decomposition, single replacement, double replacement, combustion
catalyst
substance that increases the rate of a reaction by decreasing the activation energy but does not impact reaction pathway(effect) and total energy change
precipitate
a solid as a result of two soluble ionic substances, implying also the differing levels of strength in hydration force and ionic bonding force
Molar mass shows the __ per mole of a substance, determined by using atomic mass of an element measured in amus
of grams(mass),
law of conservation of matter
matter is neither created nor destroyed
the number of atoms of an element in the Reactant ride equals the number of atoms of that element in the product side
endothermic reaction absorbs energy because the energy released is ___ than the activation energy
less
exothermic reaction absorbs energy because the energy released is ___ than the activation energy
more
intramolecular forces of attraction
ionic and covalent - ionic is stronger
intermolecular forces of attraction
hydrogen bonding(strongest), dipole-dipole, dispersion force(weakest)
synthesis reaction
two elements or compounds form one product
ex. Na + Cl –> NaCl
decomposition reaction
one reactant breaks down into two simpler substances
ex. H2O –> H2 + O
Single replacement reaction
uncombined atom, ion, or element, replaces another in a compound
ex. Zn + 2HCl -> ZnCl2 + H2
Double replacement reaction
two elements(positive ions) in reactants exchange places
ex. KBr + AgNO3 –> KNO3 + AgBr
combustion reaction
carbon containing compound burns in oxygen from air to produce carbon dioxide, water, and heat or flames
CH4 + 2O2+ CO2 + 2H2O
