化学
化学反应、化学计量、分子结构与元素性质。
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which of the following equations represents a balanced chemical equatio…
$CH_4 + 2O_2 ightarrow CO_2+2H_2O$
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define polarity in terms of strength of attractions and partial charges.
Polarity is the result of an unequal sharing of electrons in a molecule, leading to the formation of partial positive and partial negative charges. The strength of attractions bet…
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calorimetry is a method used to measure enthalpy, or heat, changes that…
$0.906\ kJ/mol$
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hydrazine (n2h4) is a fuel used by some spacecraft. it is normally oxid…
$-565.0$ kJ/mol
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recall an unanswered question from lesson 4: why is water good at disso…
Water is good at dissolving salts because of the polar nature of water molecules which can hydrate the ions in salts, breaking the ionic bonds. Salts make water more conductive be…
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part a assuming that all the energy given off in the reaction goes to h…
$8.5\times 10^{2}$
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part a assuming that all the energy given off in the reaction goes to h…
$810$
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what do we mean by partial charge? and what do we call a bond or molecu…
A partial charge is a small positive or negative charge on an atom in a molecule due to unequal electron - sharing. A bond or molecule with partial charges is called a polar bond …
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water molecule what does this model show us about charges in a water mo…
The model shows that the oxygen atom has a partial negative charge and the hydrogen atoms have partial positive charges. The negative charge is on the oxygen atom and the positive…
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question #5 of 6 which of the following substances is most likely to be…
CO₂
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question #4 of 6 covalent bonds are formed when: one atom donates an el…
Atoms share pairs of electrons
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question #3 of 6 ionic bonding generally occurs between: two metals a m…
B. A metal and a nonmetal
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question #2 of 6 which of the following compounds contains a covalent b…
$H_2O$
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sam is comparing the half - life of two isotopes of uranium. the half -…
C. \(2.81\times 10^{4}\)
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question #1 of 6 which of the following is a property of ionic compound…
Conduct electricity in molten or aqueous state
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in chemistry class, carlos calculated the number of molecules in 100 mo…
C. $6.02\times 10^{25}$
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parts b and c the next two questions pertain to silver. they have nothi…
Value: $0.235$ Units: $J\ g^{-1}\ ^{\circ}C^{-1}$
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12) choose the best answer. ____ is friction that builds up while an ob…
C. Sliding friction
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drag each tile to the correct location. identify the transformations of…
From left - to - right (assuming the order of events as described): - chemical energy to kinetic energy - kinetic energy to gravitational potential energy - gravitational potentia…
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select the correct answer. respiration is a process where many chemical…
A. Chemical energy from broken bonds is transformed into mechanical energy for muscles.
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question 3 (1 point) according to the elemental symbol below, how many …
22 protons, 25 neutrons
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question 1 (1 point) brewing tea in a pot (steeping) is an example of w…
C. Leeching
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question 2 (1 point) which of the following is the correct formula for …
B. # protons - # electrons
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this quick quiz covers information from the labster benedicts lab simul…
1. A. True 2. A. True 3. A. True
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which of the pictured molecules is the most polar molecule? select one:
The third molecule (propanol)
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describe the difference between covalent, an ionic bonds?
Covalent bonds share electrons, usually between non - metals. Ionic bonds transfer electrons from metal to non - metal, creating ions that attract.
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water how is the bonding in water different than the bonding in salts? …
The bonding in salts is ionic (electron - transfer) while in water it is polar covalent (unequal electron - sharing). The bonding in water is polar covalent.
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5. what is the purpose of the nitrogen cycle in an aquarium? a) to conv…
5. c) To maintain a healthy balance of nitrogen compounds 6. c) To remove excess organic nutrients and toxins from the water 7. c) To measure water salinity 8. a) 0.0 ppm
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oxygen has a partial negative charge due to higher electronegativity, a…
2.A. No, because CH4 is a non - polar molecule due to its symmetric tetrahedral shape. 2.B. Non - polar 3. Polar molecules: (To be filled based on actual testing with Gizmo, e.g.,…
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which of the following statements best explains how elements are groupe…
Elements are grouped according to similarities of their properties.
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which element from this portion of the periodic table chemically reacts…
I
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based on its location on the partial periodic table shown below, which …
B. B
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read the following paragraph from an essay discussing a ban on outdoor …
Main point
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chimie 311 version 3 6. dessine la formation des liaisons ioniques, cov…
# Explications étape par étape: ## Étape 1: Question 6a - $H_2O$ Le $H_2O$ a une liaison covalente polaire. L'oxygène est plus électronégatif que l'hydrogène. Les électrons partag…
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5. complete le tableau : (5 points) | | symbole de lion | nombre délect…
| | Symbole de l'ion | Nombre d'électrons total dans l'ion | Anion ou cation | Nombre d'électrons de valence de l'ion | Nombre de couches électroniques de l'ion | |--|--|--|--|--|…
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select the correct answer. which form of energy increases when a spring…
B. elastic potential energy
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polar molecule water molecules have a slight charge on the hydrogen sid…
Polar Molecule: positive; negative Universal Solvent: dissolves Naturally Occurs In all 3 States: states; gas; liquid; solid Heat Capacity: energy; temperature Cohesive: water mol…
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select the correct answer. which form of energy increases when a spring…
B. elastic potential energy
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select all the correct answers. a worker is holding a filled gas cylind…
It has gravitational potential energy because of its height. Its atoms and molecules have thermal energy.
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select all the correct answers. a worker is holding a filled gas cylind…
- It has gravitational potential energy because of its height. - Its atoms and molecules have thermal energy.
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select the correct answer. the image shows street lights powered by sol…
C. radiant energy → electric energy → radiant energy
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select all the correct answers. which two forms of energy does a hairdr…
motion energy, thermal energy
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motion energy thermal energy gravitational potential energy chemical en…
stored energy related to positions of atoms within molecules → chemical energy energy released when a nucleus splits or combines → nuclear energy energy related to an object's mov…
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chimie 311 partie b : questions ouvertes (39 points) version 3 1. vrai …
1. a. V b. F, Les masses des neutrons et des électrons sont très différentes. c. F, Les différents isotopes de l'hydrogène comptent le même nombre de protons et de électrons. d. F…
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for each of the atoms/ions below, write the full electron configuration…
1. 1s²2s²2p⁶3s²3p⁶4s²3d⁶ 2. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶ 3. [Kr]4d¹⁰5s²5p⁴ 4. [Ar]4s² 5. 1s: ↑↓; 2s: ↑↓; 2p: ↑↓ ↑↓ ↑↓; 3s: ↑↓; 3p: ↑↓ ↑↓ ↑↓ 6. 1s: ↑↓; 2s: ↑↓; 2p: ↑↓ ↑↓ ↑↓; 3s: ↑↓; 3…
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chimie 311 version 3 module 1 11. quel élément possède la plus petite é…
11. c. Rb 12. c. L'élément X appartient à la famille des gaz rares et l'élément Y à la famille des alcalins. 13. a. Un transfert d'électrons entre un métal et un non - métal 14. c…
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7. quel type de liaison intermoleculaire permettent aux molécules d’eau…
7. c. Hydrogène 8. Aucune des options n'est correcte (le bon nombre est 32 électrons) 9. a. 2 10. d. Rb
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7. quel type de liaison intermoleculaire permettent aux molécules d’eau…
7. c. Hydrogène 8. Aucune des options n'est correcte (le bon résultat est 32 électrons) 9. a. 2
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activity c (continued from previous page) 4. experiment: drag two o₂ mo…
4A. London dispersion force 4B. Molecules show weak, random attractions 4C. London dispersion force 5A. The electron cloud of the O₂ molecule gets distorted 5B. No 5C. Dipole - in…
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chimie 311 version 3 évaluation sommatique – module 1 module 1 nom : jo…
# Explications étape par étape: ## Étape 1: Réponse à la question 1 Mendeleïev a classé les éléments en ordre croissant de masse atomique. Moseley a classé les éléments en fonctio…
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phytoremediation of zinc chemical formula: zn + cuso₄ → znso₄ + cu type…
# Explicación: ## Paso1: Analizar la reacción En la reacción $Zn + CuSO_{4} ightarrow ZnSO_{4}+Cu$, un átomo de zinc (Zn) reemplaza al cobre (Cu) en el compuesto $CuSO_{4}$. ## Pa…
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read the passage and summarize it in your own words. heres an extract f…
The world generates a large amount of non - biodegradable plastic yearly, with single - use plastics being a major part of beach trash and a danger to marine life. We can make a c…
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name date class picture this 3. analyze why do people who use tobacco i…
People may ignore tobacco product warnings due to nicotine addiction, psychological denial, social factors, and disbelief in the warnings' accuracy.
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given the name for the following compounds, determine if the compound i…
| name | ionic, covalent, acid | formula | |--|--|--| | 34. dinitrogen pentaoxide | covalent | $N_2O_5$ | | 35. hydroiodic acid | acid | $HI$ | | 36. iodic acid | acid | $HIO_3$ |…
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read the following reference. martin, t. s. (2010). effects of agricult…
B. A book
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each polar molecule is known as a dipole. the attraction between the po…
1. Non - polar molecules have temporary charges due to electron distribution variations, leading to London dispersion forces. 2. Hydrogen bonding causes the attraction between $H_…
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phytoremediation of zinc chemical formula: zn + cuso₄ → znso₄ + cu type…
# Explicación: ## Paso 1: Comprender los tipos de reacciones Una reacción de síntesis es cuando dos o más reactivos forman un producto. Una reacción de descomposición es cuando un…
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question 5 which sentence uses capital letters and punctuation correctl…
B. Last fall, I withdrew from Chemistry II.
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question 8 atmosphere: which chemical element is responsible for ozone …
A. Chlorine
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question 46 2 pts which of the following describes the formation of the…
Question 46: Decompression melting of ultramafic asthenosphere produces mafic magma which cools to form mafic rocks. Question 47: naturally, inorganic, solid, chemical, ordered
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describing the properties of air. which statements correctly describe t…
Air is less dense at higher altitudes. Denser air is heavier than less dense air. Pressure is a measure of how tightly molecules are packed.
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how many total atoms? (nh4)3po4+pb(no3)4=pb3(po4)4+nh4no3
69
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atom, ion or isotope? what is this? proton neutron electron
Atom
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according to molecular orbital theory, two separate p_x orbitals intera…
Question 3: B. p and p* Question 4: D. In a stable molecule having an even number of electrons, all electrons must be paired.
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question 1 according to molecular orbital theory, two separate 1s orbit…
Question 1: B. s and s* Question 2: B. p and p*
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naming covalent compounds name the following compounds: chemical formul…
$BF_3$: boron trifluoride $Si_3P_4$: trisilicon tetraphosphide
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sarahs oncologist prescribed intensive drug treatment known as ____ for…
D. chemotherapy
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3. describe the difference between endothermic and exothermic reactions.
Endothermic reactions absorb heat from the surroundings and have products with higher energy than reactants. Exothermic reactions release heat into the surroundings and have produ…
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naming covalent compounds covalent compound: pattern: 1st nonmetal + 2n…
tetraphosphorus decoxide
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naming covalent compounds covalent compound: pattern: 1st nonmetal + 2n…
Carbon tetrachloride
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19. geologists know that wherever pressure is built up in a mass of roc…
19. a 20. c 21. c 22. c 23. b 24. d 25. d 26. d 27. b 28. a
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naming covalent compounds covalent compound: pattern: 1st nonmetal + 2n…
dinitrogen tetrasulfide
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step 1: name the type of chemical reaction 1. ex: synthesis 2. 3. 4. 5.…
1. $N_2+3H_2 = 2NH_3$ 2. $2KClO_3=2KCl + 3O_2$ 3. $2NaCl+F_2 = 2NaF+Cl_2$ 4. $2H_2+O_2 = 2H_2O$ 5. $2AgNO_3+MgCl_2 = 2AgCl+Mg(NO_3)_2$ 6. $2AlBr_3 + 3K_2SO_4=6KBr+Al_2(SO_4)_3$ 7.…
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identifying the 5 types of chemical reactions identify each of the reac…
2. single - replacement 3. synthesis 4. decomposition 5. double - replacement 6. combustion 7. double - replacement 8. combustion 9. decomposition 10. single - replacement 11. syn…
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activity: the water cycle get the gizmo ready: select the simulation ta…
A. Approximately 0.001% B. About 1.74% C. Around 68.7% D. About 0.007% E. The process by which plants release water vapor into the atmosphere through their leaves. F. Agriculture …
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teamwork in action: the process plant crew challenge name - jordan tayl…
1. Jordan. Because Jordan is great with tools and mechanics which are important in this context and the weakness is less of a problem for leadership. 2. Morgan. Since Morgan is sa…
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trevor has been asked to analyze the rhyme scheme in shakespeares \sonn…
aabb
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true or false? copper utensils and equipment can cause illness when use…
1. True; True; False; True 2. Milk, Eggs, Fish, Shell - fish, Tree nuts, Peanuts, Wheat, Soybeans 3. Hives, Swelling of face/lips/tongue, Difficulty breathing, Stomach cramps 4. C…
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activity c: intermolecular forces get the gizmo ready: select the inter…
1. Polar molecules form dipoles with positive and negative ends. 2. Non - polar molecules have temporary charges due to electron distribution variations, leading to London dispers…
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327 chemistry prep b cycle 4 homework atoms and isotopes tegrity statem…
The particle in the center of the atom (nucleus) with a positive charge is the Proton. The neutral particles in the nucleus are Neutrons. The negatively charged particles outside …
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3. the total number of protons and neutrons in the nucleus of an atom i…
3. c. mass number 4. a. average atomic mass
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327 chemistry prep b cycle 4 homework atoms and isotopes integrity stat…
## Part I: (Labeling the atom diagram): Nucleus at the center, Protons and Neutrons in the nucleus, Electron Cloud outside the nucleus, Electrons in the electron - cloud. ## Part …
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15. which of the following properties of water is not a result of hydro…
B. Ratio of hydrogen to oxygen in water molecules
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14. a solution with a ph of 5 is a. acidic b. basicc. neutral d. strong
A. Acidic
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12. a covalent bond forms when a. protons are shared between atoms. c. …
D. two atoms share a pair of electrons
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11. when an atom loses an electron, what happens? a. nothing happens b.…
B. It becomes a positively charged ion
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12. a covalent bond forms when a. protons are shared between atoms. b. …
None of the given options are correct. A covalent bond forms when electrons are shared between atoms. If we assume this is a multiple - choice with only the given options and we h…
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passage 1 excerpt from society and solitude by ralph waldo emerson the …
Both passages stress the importance of individual contemplation.
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scenario you and your crew are new hires at bayou chemical plant. your …
1. Taylor. Because Taylor is a strong communicator and can organize the team well. 2. Morgan. Since Morgan is safety - focused. 3. Hold a short team meeting where each member can …
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1) the solubility of a compound is 59 g / 100 ml in boiling methanol an…
Methanol is a better solvent for recrystallization of the compound because it has a larger difference in the solubility of the compound between high and low temperatures compared …
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question 5 (2 points) which of the following are a possible set of 4 qu…
$n = 1,l = 0,m_l = 0,m_s=+\frac{1}{2}$
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question 4 (2 points) the possible magnetic quantum numbers for l=1 are…
-1, 0, 1
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convert 25 g of mgcl₂ to atoms.
$4.752\times10^{23}$ atoms
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question 3 (2 points) the angular momentum quantum number (l) describes…
the shape of the orbital
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isótopo masa # atómico # protones neutrones electrones ²³₁₁y 23 11 11 1…
24 uma
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question 5 (2 points) which reaction depicts an reduction occurring? oa…
$\mathrm{Cl_2}+2\mathrm{e}^-\to2\mathrm{Cl}^-$
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question 4 (2 points) which of the following is a redox reaction? ○mg (…
$\text{Mg (s)}+2\text{ HCl (aq)} ightarrow\text{MgCl}_2\text{ (aq)}+\text{H}_2\text{ (g)}$
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monday: convert 25g of mgcl₂ to atoms.
$4.752\times 10^{23}$ atoms
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question 3 (2 points) the element that is oxidized in this reaction is …
B. C
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question 2 (2 points) in the reaction below, the reactant aluminum ____…
A. loses; reducing