Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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check all the ways listed below that ensure accurate reading of volume …
using subtraction to determine the volume dispensed, making sure that you read the volume with the liquid inside the pipette at eye level, ensuring that air bubbles are not in the…
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1. color is what type of property? a) physical b) chemical 2. reactivit…
1. a) Physical 2. a) Chemical 3. a) Stretching
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which statement best describes the rhyme schemes of the author to her b…
Bradstreet uses couplets throughout; Wheatley uses couplets and inverts sentences as needed for emphasis and to enhance the poem as a song of praise for creation.
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the specific heat capacity of fe is 0.449 j/g°c. a sample of fe was hea…
1. E. 297 2. I. g
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in the author to her book, the main reason bradstreet uses inversion is…
complete the rhyme scheme
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fill in the blank question is the physical and chemical processes that …
lithification
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which represents a decrease in entropy? a) nacl dissolving in water b) …
For the first question: c) condensation of steam on cold glass For the second question: b) disorder
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temperature...(select all that apply; there is more than one correct an…
B. can be given in units of Kelvin, Celsius, or Fahrenheit; D. is a measure of the average kinetic motion of molecules
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true or false 16. elements are the simplest substances. 17. electrical …
16. True 17. False 18. False 19. True 20. True 21. c. diagram C 22. b. diagram B
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question 28 (4 points) the density of water at 30.0 °c is 0.995646 g/ml…
G. 1.4504, J. g/mL
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multiple choice write the letter of the correct answer on the line at t…
1. a 2. c 3. c 4. c 5. b 6. a 7. b
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using science skills use the figure below to answer questions 23, 24 an…
23. a. liquid to gas 24. c. chemical and thermal 25. c. combustion
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the nature of matter 8. which is an example of a chemical change? a. bu…
8. a. burning wood 9. c. energy 10. b. melting ice in a glass of lemonade
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10. which of the following is an example of a change of state? a. pouri…
11. matter 12. chemical 13. energy 14. solution 15. electromagnetic
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question 16 (1 point) a hand grenade resting on the ground is primarily…
- Question 16: B. False - Question 17: A. True
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question 13 (1 point) a mixture of the unreactive noble gases argon and…
Question 13: B. False Question 14: B. False Question 15: A. True
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question 10 (1 point) the speed of light is a constant so there is no n…
Question 10: B. False Question 11: B. False Question 12: B. False
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question 5 (1 point) billie eilish is studying chemistry because she wa…
B. false
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using the following chemical reaction, classify each statement as being…
1. Reactants 2. Both 3. Both 4. Products 5. Reactants
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talaah conducts a chemical reaction and wants to know the number of hyd…
There must be 4 hydrogen atoms in the products, because the total mass is conserved.
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3. the equation below shows a chemical reaction. according to the law o…
$7.32$ grams
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general concepts: match reagents with molecules detected match each rea…
simple sugars: 3. Benedict's protein: 1. biuret starch: 2. iodine
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a scientist performs the following chemical reaction. sicl₄ + 4h₂o → h₄…
8 atoms of hydrogen
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q. 1 a compound secreted by honey - bees to paralyze intruders in their…
Carbon: 6 atoms, Hydrogen: 14 atoms, Oxygen: 1 atom
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a scientist performs the following chemical reaction: sicl₄ + 4h₂o → h₄…
$\text{SiCl}_4$ and $\text{H}_2\text{O}$
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3. using a periodic table, determine how many carbon atoms are in the f…
3
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a scientist performs the following reaction: ch₄ + 2o₂ → co₂ + 2h₂o. ho…
1 atom of carbon, 4 atoms of hydrogen, and 4 atoms of oxygen
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5. how many elements are in 3al₂o₃? 1 4 3 2 clear all
D. 2
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directions: in the hog hilton activity you learned how to fill in elect…
1. Element: Sodium (Na), Electron Configuration: $1s^{2}2s^{2}2p^{6}3s^{1}$ 2. Element: Titanium (Ti), Electron Configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{2}$ 3. Elem…
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tyra creates a model of two unknown substances, a and b. two unidentifi…
Both substances are likely mixtures because they contain two different types of elements that appear to be physically combined rather than chemically bonded. This can be further c…
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5. toby wants to create a model to show how iron (fe) changes when it r…
Iron is an element and should have only one type of atom. Iron oxide is a compound and should have two different types of atoms bonded together in a specific ratio.
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the image shows models of elements, compounds, homogeneous mixtures, an…
A. because it contains two or more types of atoms that are not chemically combined, and the substances are uniformly mixed
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a chemist has a block of aluminum metal (density is 2.7 g/ml). they dro…
6.21
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describe the way a metal will bend, scratch, dent, stretch, or break. m…
A. Mechanical Properties
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2. an atomic - level model of an element would have while 1 type of ato…
Components in a mixture are not Chemically bonded together. A mixture with uniform composition and appearance is a homogeneous mixture.
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2. an atomic - level model of an element would have while - choose the …
An atomic - level model of an element would have: 1 type of atom A model of a compound would have: 2 or more different atoms
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a chemist encounters an unknown metal. they drop the metal into a gradu…
$1.25$
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8) a 475 cm³ sample of gas at standard temperature and pressure is allo…
$345\ K$ For the second - part:
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1. directions choose the correct answer for each row. identify each sub…
Bag of nuts and seeds: Heterogenous Mixture A drink with ice cubes in it: Heterogenous Mixture Oxygen (O): Element Table Salt (NaCl): Compound Air: Homogenous Mixture
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post - lab questions: for each of the following activities, decide if i…
1. Change: Chemical change Justification: Wood reacts with oxygen to form new substances like CO₂, H₂O and ash. 2. Change: Physical change Justification: Only state change from li…
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you have a sample of each of the following five metals, with the mass a…
E. silver, mass = 215 g, d = 10.5 g/cm³
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a chemist is trying to identify an unknown metal and finds that 25.0 cm…
C. copper, $d = 8.98\ g/cm^{3}$
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read the excerpt from the author to her book. thou ill - formd offsprin…
A. A, B, A, B
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4. what would be the new volume if 250 cm³ of gas at 25°c and 730 mm pr…
$220\ cm^3$
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4. in the simulator, experiment by adding each type of particle to your…
4. Protons 5. No 6. Yes 7. Protons and neutrons 8. Yes 9. 2 10. 5 11. 8 12. It becomes a negatively - charged ion.
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chemistry—unit 2 worksheet 4 on each of the problems below, start with …
(1) The new volume is approximately $163mL$. (2) The new pressure is approximately $94.9psi$. (3) The new pressure is approximately $1.67atm$.
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which oral condition does chemotherapy make a patient more susceptible …
Mucositis
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7) chlorine has two possible isotopes. you must use at least one atom o…
Cl - 35 atoms: 77.5% Cl - 37 atoms: 22.5%
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identifying jargon identify the use of jargon in the excerpt by sorting…
Not Jargon: far door, hot side Jargon: air lock, chemical shower, decon cycle, hot agents
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a thermometer shows a temperature of -20\frac{3}{4} degrees. a chemist …
-20.75
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intermediate level problems: 6. the following are the results of analys…
The two samples are different compounds, and the data follows the law of multiple proportions.
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adhesive forces between water molecules and glass molecules help water …
Water rises farther in a narrow glass tube than in a wide glass tube. Water molecules are held together by hydrogen bonds as they rise in a capillary tube.
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a scoop - shaped concave meniscus forms when adhesive forces between a …
oil: Cohesive forces are greater than adhesive forces. water: Adhesive and cohesive forces are equal. mercury: Adhesive forces are greater than cohesive forces.
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in chemistry class, teresa was aware that she was writing down her teac…
consciously aware of her experience.
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dr. liza conducted a sleep study in which half of the volunteers were r…
Melatonin
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determine whether each statement is true or false. water molecules at t…
Water molecules at the surface form hydrogen bonds with only the molecules next to and below them: False Molecules at the surface of water repel molecules below the surface: False…
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estimate large and small quantities quick check the radius of a hydroge…
0.000000053
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polar water molecules form hydrogen bonds with each other. in liquid wa…
A slightly negative oxygen atom in a water molecule forms a hydrogen bond with a slightly positive hydrogen atom in another water molecule.
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water is made of one oxygen atom covalently bonded to two hydrogen atom…
In a molecule of water, the oxygen atom shares electrons with each hydrogen atom. Oxygen also has two non - bonding pairs of valence electrons. Because valence electrons are more …
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use the phase diagram of substance x below to find the melting point of…
(Assuming the graph reading gives $T_{K} = 300$ K) $T_{C}=300 - 273.15=26.85^{\circ}C$ (The actual value will depend on the accurate reading from the given phase - diagram)
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question 5 (1 point) indicate whether the following sentence is true (t…
False
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29 matching 1 point please match the element to its kind. argon chlorin…
Argon - Noble gas Chlorine - Non - metal Sodium - Metal Iron - Metal Oxygen - Non - metal
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consider the same reaction: 2 molecules of ethylene (c₂h₄) react with 1…
2
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2. how does the change in energy of a chemical reaction predict whether…
2. A negative Gibbs free - energy change ($\Delta G$) indicates a spontaneous reaction likely to occur; positive $\Delta G$ means non - spontaneous; $\Delta G = 0$ is equilibrium.…
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acetaldehyde is a substance commonly used in chemical factories. it is …
H: 8 C: 4 O: 2
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13 fill in the blank 5 points atoms of the same element that have diffe…
13. Isotopes 14. Physical
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consider the same reaction: 1 molecule of nitrogen (n₂) reacts with 3 m…
2
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3. explain are all compounds molecules? why or why not? 4. compare ioni…
No, because some compounds like ionic compounds are not held together by covalent bonds to form molecules. ### 4.
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10 numeric 1 point what is the atomic number of sulfur? answer 11 numer…
10. 16 11. 22
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ammonia is commonly used as a fertilizer for plants. it is made when ni…
| Chemical element | Number of atoms in products | | ---- | ---- | | H | 6 | | N | 2 |
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question 2 of 12 points possible: 1.00 how can you improve your ability…
B. Place a piece of white paper under the analyte flask throughout the titration.
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6 fill in the blank 1 point the symbol for chlorine is type your answer…
6. Cl 7. 12 8. 29
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ethanol is a chemical that is used in many hand sanitizers. it is produ…
1
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2 fill in the blank 1 point the symbol for silicon is type your answer.…
The symbol for silicon is Si. The symbol for sodium is Na. The symbol for iron is Fe.
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use the phase - diagram of substance x below to find the temperature at…
(The specific temperature value needs to be read from the actual phase - diagram which is not provided with clear scale values in the description. But the process is as above to f…
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is region a likely hydrophobic or hydrophilic? explain your answer. due…
Region A is hydrophobic because it consists of long non - polar hydrocarbon chains. Region B is hydrophilic because it contains polar and charged functional groups (phosphate and …
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does cholesterol contain many partial charges, or very few partial char…
Cholesterol can form very few hydrogen bonds with water, because it has very few partial charges.
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part 1 analyze the overall structure of cholesterol. how does the numbe…
Part 1: Cholesterol has more nonpolar covalent bonds than polar covalent bonds. Part 2: Very few, because it is primarily made of nonpolar bonds.
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in an atom, in stable atoms, the number of protons, the number of neutr…
| Element | Atomic # | Atomic Mass (Rounded to the whole number) | # of Protons | # of Neutrons | # of Electrons | |---|---|---|---|---|---| | Hydrogen (H) | 1 | 1 | 1 | 0 | 1 | |…
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9 fill in the blank 1 point when comparing the ionization energies betw…
1. Phosphorus 2. stronger 3. remove a valence electron
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the educated reader uses the language of authors craft to discuss liter…
To answer the question, one must first identify poetic elements like imagery, metaphor, rhyme - scheme, etc. in "Recuerdo". Then, analyze how each element contributes to the theme…
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multiple choice 1 point which element has a higher ionization energy an…
C. Bromine. More energy is needed to remove an electron because there is more attraction between the valence electrons and the protons in the nucleus.
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6 fill in the blank 1 point when comparing the ionization energies betw…
1. Platinum 2. stronger 3. remove an electron
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5 multiple choice 1 point which element requires more energy to remove …
B. Carbon
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4 fill in the blank 1 point which element requires more energy to remov…
Bromine
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3 multiple choice 1 point which element shown below requires more energ…
A. Radon
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2 multiple choice 1 point which element shown below requires more force…
B. Krypton
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exit ticket: ionization energy 1 fill in the blank 1 point for elements…
more protons
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in words, the expression means: oxygen is more electronegative than nit…
O:——C
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lets put some of these ideas together. summarize the information you ju…
- Bond polarity is caused by differences in electronegativity. - Bond polarity results in partial positive and partial negative charges on the atoms involved. - With respect to el…
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9 0/1 point consider the elements listed below: zirconium strontium tin…
1. **Question 9**: Tin has the strongest coulombic attraction among Zirconium, Strontium, Tin, Silver. 2. **Question 10**: Aluminum has a stronger force of attraction between the …
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the ball - and - stick model below is of a sugar called glucose. (gluco…
C. The correct molecular formula for glucose is \(C_{6}H_{12}O_{6}\) D. Glucose contains 6 carbon atoms, 6 oxygen atoms, and 12 hydrogen atoms.
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13 multiple choice 1 point why does nickel (ni) have more coulombic att…
Nickel has less energy levels causing the valence electrons to be closer to the protons in the nucleus.
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lets check your understanding. drag and drop the correct structural for…
Ammonia $NH_3$: The structural formula with a nitrogen atom in the center and three hydrogen atoms bonded to it. Water $H_2O$: The structural formula with an oxygen atom in the ce…
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drag and drop the correct molecular formula to match it with each molec…
First molecule: $NH_3$ Second molecule: $H_2O$
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12 fill in the blank 1 point when comparing magnesium (mg) and phosphor…
Phosphorus; are in the same period; phosphorus has more protons; a higher effective - nuclear charge
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11 multiple choice 1 point why does oxygen (o) have a stronger coulombi…
Oxygen's valence electrons are on the same energy level as Carbon's causing their valence electrons to be about the same distance from the nucleus. However, Oxygen has more proton…
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rank the amount of time that a water molecule spends in each of the fol…
Living things (plants & animals), Rivers, Lakes and swamps, Groundwater
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10 fill in the blank 1 point when comparing the coulombic attraction be…
- First blank: Gallium (Ga) - Second blank: Gallium (Ga) - Third blank: closer to
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9 fill in the blank 1 point consider the elements listed below: zirconi…
Silver