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40 Cards in this Set
- Front
- Back
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What did Democritus think of? (3) Hint: What is an atom? |
-the smallest piece of matter is indivisible -smallest particle of matter was the atom -atoms are infinite in number, separated by empty space, always moving, and can join together |
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What did Aristotle and Plato incorrectly think of? (1) |
-believed matter made of fire, Earth, water and air |
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What did Dalton discover? (3) Hint: what model did he create? |
-matter made of tiny, indivisible particles called atoms -atoms of the same element are alike, atoms of different elements are different -compound are of 2 or more atoms -billiard ball |
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What did Thomson discover? (1) What was the model he used? (1) What was the experiment he did and what happened? What was used? (3 explanation points) |
-atoms contain negatively charged particles called electrons spread throughout positively charged sphere -plum pudding model/chocolate cookie --vely particles shot at +vely and -vely e-plates -cathode ray (-vely charged particles) deflected from -vely charged electric plate -since gas known to be 0, therefore, must have +vely charged particles in atom too |
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What did Rutherford think would happen with the aluminum foil experiment and why? (1) What happened? (1) |
-e-supposed to go straight through with little deflection because soup is positive and throughout, therefore weak, so should not deflect -most e- go through, but some deflect back |
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Why? (3) Conclusion Hint: what did he discover? (3) |
-the alpha particles do not always pass, therefore, atom must have + center that deflects -go through because mostly empty space-center should be heavy to deflect so + particle have more mass than - particles-center=nucleus -# of p=e -volume of + charge very small compared to atom because little deflected |
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What are the problems with the Rutherford's model? (2 facts and 2 explanations) |
1. opposite electric charges attract, so --vely charged e-s should be pulled into + nucleus, but do not 2. accelerating electrically charged particles continuously emit raditation -the orbiting e- should lose energy and spiral into the nucleus and atom should collapse, but atoms are very stable |
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What did Chadwick discover? (2) How did this help? (1) |
-neutron -mass of p about mass of n -this helped explain the existence of isotopes because different atoms of the same element had different masses, so neutrons affected this difference, therefore, the atoms had diff number of neutrons |
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How does light exist? How does energy exist? |
-light is a form of energy that is quantized in photons, which exhibit properties of waves and particles |
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What are electromagnetic waves? (2) What is electromagnetic radiation? (1) |
-E waves are waves formed when electricity and magnetism change together -E waves are produced by the motion of electrically charged particles -E radiation is a form of energy transmission through a vacuum or medium in which electric and magnetic fields are propagated as waves |
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What did Planck study? (1) What did he suggest? (1) Equation (1) |
-he studied black bodies (black object which does not reflect light and emits various energies as a result of temp) ex, wires -suggested that energies of atoms not continuous, but energy exists in quantized amounts -E=nhv |
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What is the photoelectric effect? (1) What did Einstein determine? (2) |
-pe: light shone on metal leads to the ejection of electrons from the metal's surface -e- not able to leave surface unless a specific frequency of light was absorbed by the metal, this freq corresponds to a specific wavelength and therefore energy -diff elements need diff energies |
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How do wavelengths and energy relate? (2) |
-when freq of wavelength small, energy small, wavelength long -when freq of wavelength large, energy large, wavelength short |
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What is an Emission Spectra? (2) What is the diff and sim between continuous and line? (2) |
-light reflected that is seen using a spectroscope -we can only see wavelengths of light in the visible light spectrum -continuous is white light where we cannot distinguish any specific wavelength -elements emit certain wavelengths of light, which results in a line spectrum |
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What are the six principles of Bohr's model? (6) |
1. e-s possess specified quantities of energy 2. e-s exist in fixed regions of space called orbits 3. each energy level is a specific distance from the nucleus, where the first orbit has the smallest radius and the second is larger 4. e-s closer tot eh nucleus have less energy, therefore, e-s further on higher energy level have more energy (e-s must absorb energy to get to higher level) 5. there is a limit to the # of e-s in an orbit 6. e-s can change their energy only by undergoing a transition from one stationary state to another |
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How can we see light? (3) |
1. en e- would absorb energy in the form of photons to get excited and transition to a higher energy level (needs all required energy to get to next level, otherwise energy goes elsewhere) 2. at a higher energy level, the e-s are unstable, so emit energy when fall back down to lower level to be stable 3. if it falls to an energy level which emits wavelengths in the visible light spectrum then see light |
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At what levels does energy emit in a specific spectrum for Hydrogen? (3) Correction: energy emitted not light: for proper vocab |
-when e- drops to energy level 2 then in visible region -when to level 3 then infrared region -when to level 1 than UV |
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Why did each gas show a colour only when electricity was passed through the discharge tube? (4)
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-energy from the e- of current electricity gets given to the e- of the gas -e- of gas jumps to a higher energy level after absorbing the energy -the e- are unstable int eh higher energy level ( and in excited state), so they fall to a lower energy level -if the energy emitted by the e- as it falls corresponds to wavelength in the visible light spectrum then colour is seen |
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Why do we observe 4 lines in the H line spectrum if it only has one e-? (3) Correction: talk about energy change not distance |
-as the electrons fall from higher levels to lower levels, they release photons -different "falls" create different colors of light -the visible wavelengths are caused a by single electron making the different transitions |
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What is the order of light from shortest wavelength to longest? (6) Why do blue and light blue have the same quantum number (n)? (1) |
-violet, blue, light blue, yellow, red, dark red -same colour, but different tones in subshells (angular momentum quantum number) (l) |
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What is De Brogile's idea called? (1) What is the explanation? (1) Which equations did DeBrogile use?(1) What was the equation for the isolation of wavelength? What did he conclude? (2) How did he relate mass and wavelength? What were the interpretations? (4) |
-wave/particle duality -argued that since light can display wave andparticle properties, then matter can also be a particle and a wave too - nhv=mc^2 - square root of 1 over m is indirectly proportional to wavelength (lamda) - when mass is large, wavelength is short and the substance behaves like a particle, ex people -when mass is small, wavelength long and substance behaves as waves |
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What did Schrondinger discover? (4) |
-formulated the hydrogen wave eq by considering the e- to be a wave -determined the energy of an e- -energy of e- inside atom were quantized, so only certain energies were able to be absorbed/emitted -derived math eq to find the volume where an e- most likely will be |
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What did Heisenberg discover? (1) What is this called? (1) What does this imply? (1) What is the probability model? (1) What do the math eqs rep? (1) |
-you can never know the position and momentum (speed) of an electron simultaneously -Heisenberg uncertainty principle -implies we cannot know the exact path of an electron as it moves around the nucleus, thus, it can't be traveling in an orbit -math equations plot 3D regions of space called orbitals where probability of finding e- high -diff eq yield diff shapes like s,p,d,f |
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What is quantum mechanics? (1) |
-the application of quantum theory to explain the properties of matter, particular e-s in atoms |
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What is electron probability density? (1) |
the prob of finding an e- at a given location, derived from wave eqs and used to determine the shapes of orbitals, also called e- prob distribution |
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What are the 5 rules for the Quantum Mechanical Model of the Atom? (5) |
1. the location of the es in atoms is defined by a math eq 2. these eqs give the volume of space where the probability of finding the e- is high 3. the region of space if called an electron cloud (orbital) 4. the shape of this region of space depends on the energy level 5. it is impossible to know the precise position and motion of an e- simultaneously because e-s never stop moving |
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What is the Principle Quantum Number? (4) How can we derive the max number of e-s found in a specific energy level? (1) |
-n -whole number -relates to an e-s average distance from the nucleus -equals the # of orbital types that exist in each energy level ex if n=2 then there are 2 orbital types -max number of e-s= 2n^2, n=energy level |
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What is l? (7) Hint: what is l=#? |
-angular-momentum number -determines type of orbital (shape) - l=0,1,2,...n-1 ex. if n=3 then l=0,1,2 -when l=0, s -when l=1, p -when l=2, d -when l=3, f |
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What is the s-orbital? p-orbital? d-orbital f-orbital? (4 with detail) aka subshells |
s: ball, max 2 e-s, l=0 p: barbell, max 6 e-s, x,y,z 2e- each, directions, l=1, orbitals do not overlap (only ml overlaps in energy levels) d: l=2, 2e- each, max 10 e-s f: l=3, 2e- each, max 14e-s Hint: for p,d,f count the number of elements in each row section to determine number of orbital types then * 2 |
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What is ml and ms? (2 with detail) |
ml: magnetic quantum number, sublevels, describes the orientation of an atomic orbital in space relative to the other orbitals in the atom, whole numbers ex, 5 types of orbitals then # are -2,-1,0,1,2 Hint: the further the orbitals are from the nucleus, the closer together, and the more overlap ms: spin quantum number, +1/2 is clockwise spin of e-, -1/2 is counterclockwise spin of e- |
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What is the Aufbau Process? (1) |
-the theory that an atom is built by the addition of e-s, which fill orbitals starting from the lowest to highest available energy orbital |
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What is Hund's rule? aka Principle of Maximum Multiplicity (2) |
-when e-s are added to subshells of the same energy level, one is placed in each before any pairing of e-s -when e- first added, they are added with the same spin up |
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What is the Pauli Expansion Principle? (1) |
-no 2 e-s have the same 4 quantum numbers, each electron unique |
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What is ferromagnetism? (1) What is paramagnetism? (1) |
-the very strong magnetism commonly exhibited by material that contain ni, fe, co, applies to a collection of atoms (with presence of magnetic field atoms align even when removed unless disturbed) -the weak attraction of a substance to a magnet, applies to individual atoms (single pairs with same spin is weak) |
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What is the definition of isoelectronic? (1) What is isoelectronic configurations? (1) |
-having the same # of e- per atom, ion, or molecule -atoms to gain stability have the same electronic configuration with noble gases, so diff elements have the same electronic configurations |
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What is the overall geometry? What is the molecular geometry? (2) Hint: refer to page for all labels and angles do not need to draw lines, bubbles, wedges for lone pair electrons |
-OG: # LPE + BPE -MG: only # of BPE |
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What are resonance structures? (1) |
-e- said to delocalize, so can form bonds differently, if same elements in molecule |
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Which repulsive forces in molecules are strongest? Weakest? (2) |
-strongest repulsive forces are bw LPE -weakest repulsive forces are bw two BPEs |
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What is the VSEPR theory? (1) |
-a method to determine the geometry of a molecule based on the idea that e- pairs are as far apart as possible |
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When is a molecule nonpolar? (3) |
-no polar covalent bonds -if present then charges cancel out -only cancel out if overall geo= molec geo and all atoms around central atom the same |
