Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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14. what is the primary reason electron pairs repel each other? a. they…
C. They are negatively charged.
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13. which of the following statements is true about nonpolar molecules?…
A. They do not have significant dipole moments
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12. which molecular geometry is associated with a central atom having s…
c. Octahedral
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11. which molecular shape is associated with a central atom that has th…
A. Trigonal pyramidal
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10. which of the following molecules has a trigonal pyramidal shape? a.…
c. Ammonia ($NH_3$)
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8) draw a picture of daltons model of an atom and upload the file here …
You would draw a simple solid sphere to represent Dalton's model of an atom. Since this is a drawing task and not something that can be directly provided in text, the description …
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9. what is the predicted molecular geometry of a molecule with five bon…
B. Trigonal bipyramidal
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8. which of the following is an example of an ionic compound? a. sodium…
A. Sodium chloride (NaCl)
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7. which of the following substances is soluble in a polar solvent like…
B. Ethanol ($C_2H_5OH$)
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7) choose all that apply. select the five postulates proposed by dalton…
- Atoms cannot be created or destroyed (law of conservation of mass) nor can they be divided into smaller particles. - All matter is composed of extremely tiny particles called at…
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2. which molecule is nonpolar due to equal sharing of electrons? a. oxy…
a. Oxygen ($O_2$)
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5) choose the correct scientific notation. what was a limitation of dal…
5. The model was much simpler than the real system of an atom. 6. - proposed by Joseph Proust and known as the law of constant composition: law of definite proportions - proposed …
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3) choose the best answer. which law is also one of daltons postulates?…
3. law of conservation of mass 4. billiard ball model
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1) choose the best answer. which law did dalton propose? law of conserv…
1. C. law of multiple proportions 2. C. experiments with different gas pressures
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the extraordinary properties of water a water molecule (h2o) is made of…
three; oxygen atom; hydrogen atoms
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18. choose the best answer. the relationship between the mass and volum…
18. density 19. It is a molecule.
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16. choose the best answer. glucose contains both carbon and hydrogen. …
16. B. organic 17. B. reactivity, C. flammability
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14. choose the best answer. the smallest unit of an element that mainta…
14. C. atom 15. A. Scale
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12. when a substance changes in a way that does not change its composit…
12. D. physical 13. save time and money before making a product, study things that are very small
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iron oxide (rust) does not contain carbon. iron oxide is a(n) ____ comp…
1. A. inorganic 2. A. extensive
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8. in order for elements to form a compound, which two things must happ…
For the first question: must chemically combine, must be in definite proportions For the second question: Water is clear, Water is polar, Water has poor thermal conductivity
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look at the picture. then, choose the best answers. 4. choose the best …
4. extensive 5. chemical 6. physical 7. intensive
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3. choose the best answer. a(n) ____ property does not depend on the am…
D. intensive
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1. choose the best answer. a(n) ____ substance is made up of two or mor…
1. D. compound 2. D. chemical
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10) choose the best answer. margaret hutchinson rousseau was a pioneer …
10) chemical engineering 11) limitations of modeling an approximation of what is observed - simplicity unable to account for different outcomes that happen in real systems - varia…
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8) choose the best answer. which scientist uses models to invent produc…
8) chemical engineer 9) to understand how polyethylene behaves when shaped
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7) choose the best answer. what is the purpose of developing the follow…
to learn more about the process of forming a precipitate
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1.3a models of the atom select the best answer for each of the followin…
5 - 1: a. Contains separated particles 5 - 2: b. Can be disrupted 5 - 3: c. Vaporization 5 - 4: d. Gas to liquid
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a scientist discovers a new chemical on the earth. how would molecular …
by showing the chemical's structure
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a student conducts an experiment to determine how the temperature of wa…
perform multiple trials for each measurement instead of just one
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how do you distinguish a compound verses an element? what is the differ…
An element consists of one - type of atom and is indivisible by chemical reactions. A compound is formed by chemical combination of different elements in a fixed ratio.
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name the following hydrates 27. cr₂(co₃)₃•h₂o 28. caso₄•2h₂o 29. fepo₄•…
27. Chromium(III) carbonate monohydrate 28. Calcium sulfate dihydrate 29. Iron(III) phosphate trihydrate 30. $CuSO_3\cdot 5H_2O$ 31. $Co_2(CO_3)_3\cdot 4H_2O$ 32. Lead(II) sulfide…
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each layer of earth has different physical and chemical properties. thi…
Composition of the layers
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5) choose all that apply. which two of these are required for a compoun…
5) C. must chemically combine, D. must be in definite proportions 6) Water's polarity causes hydrogen - bonding between water molecules, resulting in high surface tension, high he…
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istry a phs (ne) / unit 2 - atomic structure which two of these are pro…
Water has poor thermal conductivity. Water is clear. Hydrogen atoms are not perfectly held on opposite sides of oxygen.
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water is polar waters unique properties are due to its being a polar mo…
Drag the negative symbol (-) to the oxygen - containing side (red sphere) and the positive symbol (+) to the hydrogen - containing side (blue spheres).
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1) drag and drop the definitions with the terms. a substance made up of…
1. "a substance made up of two or more atoms that are chemically bonded together" - molecule; "a compound that contains carbon and hydrogen" - organic compound; "a compound that d…
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give formulas for the following ionic compounds: 22. cobalt(ii) nitrate…
22. $Co(NO_{3})_{2}$ 23. $Ag_{3}N$ 24. $Al(C_{2}H_{3}O_{2})_{3}$ 25. $BaSO_{4}$ 26. $Cu_{2}CrO_{4}$
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7) look at the picture. then, answer the question. is density an intens…
intensive property
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6) look at the picture. then, answer the question. the density of epiba…
physical property
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4) look at the picture. then, answer the question. the frog is blue. is…
physical property
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3) check the box if the statement describes a chemical property or a ph…
malleability: Physical property boiling point: Physical property color: Physical property ductility: Physical property toxicity: Chemical property density: Physical property react…
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name the following ionic compounds 17.fe2o3 18.hg2s 19.(nh4)3po4 20.pb(…
17. Iron(III) oxide 18. Mercury(I) sulfide 19. Ammonium phosphate 20. Lead(IV) carbonate 21. Chromium(III) oxalate
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2) drag and drop the terms with the definitions. occurs when two or mor…
"occurs when two or more substances combine to make a new substance": chemical change "a relationship between the mass of matter and the space or volume that it occupies": density…
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1) drag and drop the terms with the definitions. anything that has mass…
1. matter 2. atom 3. pure substance 4. atom (closest in the given options to the concept of the smallest unit of matter with properties) 5. compound
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give formulas for the following acids: 13. hypochlorous acid 14. hydrob…
13. $HClO$ 14. $HBr$ 15. $HIO_4$ 16. $HNO_2$
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practice 1. fill in the following table with the correct information. |…
| Atom/Element | Atomic # | # of Protons | # of Neutrons | Mass # | |---|---|---|---|---| | Hydrogen - 1 | 1 | 1 | 0 | 1 | | Hydrogen - 2 | 1 | 1 | 1 | 2 | | Helium - 3 | 2 | 2 | …
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name the following acids: 9. hclo3(aq) 10. h2cr2o7(aq) 11. hc2h3o2(aq) …
9. Chloric acid 10. Dichromic acid 11. Acetic acid 12. Sulfuric acid
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give formulas for the following binary covalent compounds: 5. tetrasulf…
5. $S_4F_{10}$ 6. $ClI_3$ 7. $N_2S_5$ 8. $SiH_4$
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name the following binary covalent compounds: 1. s₂o₆ 2. ccl₄ 3. p₂s₇ 4…
1. Disulfur hexoxide 2. Carbon tetrachloride 3. Diphosphorus heptasulfide 4. Boron tribromide
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predicting characteristics by metal type. use the periodic table to loc…
Lithium: is most reactive Barium: has 2 valence electrons Cobalt: forms colorful compounds
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2.14 indicate if the zeros are significant in each of the following mea…
a. Both zeros are significant. b. Both zeros are significant. c. None of the zeros are significant. d. None of the zeros are significant. e. The zero is significant.
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comparing alkali metals with alkaline earth metals match the property w…
Soft - Alkali Metals Extremely reactive - Alkali Metals 1 valence electron - Alkali Metals 2 valence electrons - Alkaline Earth Metals Harder, more dense - Alkaline Earth Metals
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group 18 is known as the ____? 5 points kings and queens of the periodi…
1. C. The Noble Gases 2. A. H.G.J. Moseley 3. D. neutrons
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as you move from left to right across the second period of the periodic…
1. Ionization energy increases 2. Group 1 3. Mercury
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compared with the electronegativities of the elements on the left side …
C. higher
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how does atomic radius change from top to bottom in a group? it tends t…
It tends to increase
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juliet started working with a radioactive substance. in 1997, she start…
cobalt - 60
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radioactive isotope|half - life rubidium - 91|58.4 seconds iodine - 131…
rubidium-91
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a poem with fourteen lines and a mixed rhyme scheme is a foil couplet s…
D. sonnet
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question from a molecule point of view, how is liquid water at 100° c s…
Similarity: Both consist of H₂O molecules. Difference: In liquid water, molecules are closer - packed with stronger intermolecular forces and less freedom of motion; in water vapo…
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who arranged the elements according to atomic mass and used the arrange…
1. D. Dmitri Mendeleev 2. D. Kr 3. A. In, 49 protons, 49 electrons
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a repetition of properties occurs when elements are arranged in order o…
1. periodicity 2. Metal
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classify the figures shown above as depicting a chemical reaction, a ph…
Without specific labels for each image's classification, here's a general way to think: - Chemical Reaction: Images with chemical equations like $2H_2O_2(aq) ightarrow 2H_2O(l)+O_…
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indicate which three of the following five are homogeneous mixtures. ch…
A. Sweat, B. Compressed air in a scuba tank, E. An 18K gold ring
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a sample of neon in two different states of matter are shown. the arrow…
Molecular kinetic energy
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4. in the combustion of propane (c3h8), which gases are produced? oxyge…
D. Carbon dioxide and water vapor
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the rungs are held together by ___ bonds covalent ionic molecular
covalent
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06 question (1 point) what is the chemical formula for the following co…
$C_6H_4Cl_2$
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read the paragraph, then choose the word that best completes the senten…
C. examined
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read it! scientist albert einstein is revered as one of the greatest ph…
D. intersected
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you will be administratively suspended if you have a breath or blood al…
D. 0.08
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5. what is the end result of a chemical reaction?
Products
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generally speaking, what types of hazards should you protect yourself f…
A. Sharp objects, B. Splattering, C. Corrosive chemicals, D. Spills, E. Flame
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what would be the benefit of taring the scale with the beaker? we can n…
B. No calculation is needed to determine the weight of the sodium chloride.
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where do you need to orient your eye level to take an accurate reading …
Exactly parallel to the meniscus
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indicate the answer choice that best completes the statement or answers…
1. b 2. d 3. d 4. a 5. d 6. a
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1. a client consults with a cosmetologist about a recent problem with d…
1. d 2. d 3. d 4. a 5. d 6. a
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acetone and sodium chloride both have a similar mass. explain why their…
Acetone is a covalent compound, while sodium chloride is an ionic compound. Covalent compounds have weak attractions between molecules, resulting in low melting points.
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examine the lewis structure. h—h—o: what is incorrect in the structure?…
The middle hydrogen is surrounded by 4 electrons. The middle hydrogen is bonded to 2 elements.
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on a sheet of paper, draw the lewis structure for the following compoun…
All of the features: correct number of P and Cl atoms, P as the central atom, line (single bond) between P and each of the five Cl atoms, six dots (electrons) associated with each…
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on a sheet of paper, draw the lewis structure for the following compoun…
All of the features should be checked: - correct number of S and Cl atoms - S as the central atom - single bond between S and each of the two Cl atoms - six dots (electrons) assoc…
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on a sheet of paper, draw the lewis structure for the following compoun…
The Lewis structure has a sulfur atom in the center with two single bonds to two chlorine atoms. Each chlorine atom has 3 lone - pairs of electrons and the sulfur atom has 2 lone …
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identify arrows pointing to bonding electrons. a, b, d complete identif…
a
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identify arrows pointing to bonding electrons. a, b, d complete identif…
a, b, d
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identify arrows pointing to bonding electrons. identify arrows pointing…
Arrows pointing to nonbonding electrons: c
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identify arrows pointing to bonding electrons.
a, b, d
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identify arrows pointing to bonding electrons.
Arrows a, b, c
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11. solve using the quadratic formula: 2x² + 3x = 20. in chemistry, any…
$x=\frac{5}{2}$
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12. determining the mass of an object three times gave the following re…
Mean mass: 9.2 g; Average deviation: 0.07 g
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8. why should you never determine the mass of a hot object? 9. why is i…
It can damage weighing equipment and cause inaccurate readings due to hot air currents. ### 9.
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26) read all procedures thoroughly before entering the laboratory. * 1 …
26) A. True 27) A. True 28) B. False 29) B. False
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22) work areas should be kept clean and tidy. * 1 point true false 23) …
22) A. True 23) B. False 24) A. True 25) B. False
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6) after completing an experiment, all chemical wastes should be * 1 po…
6. B. disposed of according to your instructor's directions 7. A. discuss the issue with your instructor 8. D. away from all people
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3) approved eye protection devices (such as goggles) are worn in the la…
3. any time chemicals, heat or glassware are used 4. advise your science instructor that you wear contact lenses 5. ask the instructor before proceeding
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exercise e (1) write the letter of the correctly capitalized expression…
1. B 2. B 3. A 4. A 5. A 6. B 7. A 8. A 9. A 10. B 11. A 12. B 13. B 14. A 15. A 16. A 17. A 18. B 19. A 20. B 21. B 22. A 23. B 24. A
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12 multiple choice 2 points superfund and rcra are administered and enf…
12. the United States EPA. 13. chemical treatment and landfilling.
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multiple choice 2 points what steps are involved in the recycling of ma…
8. sorting, cleaning, and crushing 9. Anything can be composted.
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2. if you start with a substance as a solid, what will happen to the mo…
The molecules will vibrate more vigorously. As more heat is added, the solid may eventually melt and the molecules will be able to move more freely.
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2. if you start with a substance as a solid, what will happen to the mo…
The molecules will vibrate more vigorously. As more heat is added, the intermolecular forces are overcome and the solid may melt, allowing the molecules to move more freely.