化學
化學反應、化學計量、分子結構與元素性質。
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une solution de sulfate de cuivre (cuso₄) a une concentration de 1,2 mo…
E. 0,5 mol
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which statement is true about alkali metals? a) they arent very reactiv…
C) Some of them explode when exposed to water.
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the purpose of an indicator is to a) test and determine the ph values o…
A) test and determine the pH values of unknown solutions.
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preguntas: 1. ¿por qué parece que la vela pierde masa, aunque no lo hac…
### Pregunta 1 # Breve Explicación: Cuando una vela arde, el cera reacciona con el oxígeno del aire en una reacción de combustión, produciendo dióxido de carbono ($\ce{CO_2}$) y v…
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which classification of matter includes materials that can no longer be…
A) Compound
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the valence of aluminum is +3, and the valence of chlorine is −1. the f…
C) \(Cl_{3}Al\)
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whats the percent composition of sulfur in h₂so₄? a) 2.1% b) 65.2% c) 3…
C) 32.7%
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a chemical reaction in which two elements or radicals change places wit…
A) double replacement
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a chemical reaction in which two or more substances undergo a chemical …
(Assuming the correct option, say if there was a C) synthesis, then C. But since the visible options don't have it, there's an error. However, if we assume a misprint and the inte…
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the molecular mass of sodium oxide (na₂o) is a) 61.97894. b) 45.97954. …
A) 61.97894
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the smallest unit of an element that has all of the properties of the e…
B) atom.
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all of the following are assumptions presented by daltons atomic theory…
A) all atoms of different elements are alike in size, shape, and weight.
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8. the reaction a → products is first order in a. if 1.60 g of a is all…
The half - life of the reaction is $\boxed{22.5\ min}$
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organic chemistry is the study of compounds containing a) carbon. b) ni…
A) carbon.
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regarding the formula al₂o₃ which of the following is accurate? a) the …
Option A is inaccurate (as subscript 2 in $\ce{Al_{2}O_{3}}$ represents 2 Al atoms, not 2 O atoms). If we assume we need to state the accuracy of A, the answer is that A is incorr…
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which of the following chemical equations is balanced? a) nh₃ + h₂o → 2…
There is an error in the given options as none of the provided chemical equations are balanced. However, if we assume possible typos: - If option B was \(2NaCl + H_2SO_4 \to 2HCl …
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graded qu... x 0:00:15 elapsed which of the following formulas represen…
C) \( C_2H_4 \)
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what product is formed in the hydration reaction shown below? chemical …
The first option (the structure with \(OH\) on the tertiary carbon, i.e., the first circular - option structure) ### Second Question (Unsaturated Hydrocarbon)
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check the box under each compound that exists as a pair of cis/trans is…
We check the box under the compound $\boldsymbol{\ce{HO - CH = CH - OH}}$. If none of the compounds had met the criteria, we would check "none of the above", but in this case, $\c…
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which term correctly describes the relative position of the two substit…
ortho ### Second Question (Cis - Trans Isomerism)
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a cyclic alkene with ch₃ group + h₂ (pd catalyst) → options: (1) cycloh…
The second option (the structure with a cyclohexane ring and a \( - CH_3\) group attached) ### Question 11 (IUPAC Naming of Alkene)
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agrocybin is isolated from edible mushrooms and is reported to be an an…
s: (1) \( 109.5^\circ \) (2) \( 180^\circ \) (3) \( 180^\circ \) (4) \( 120^\circ \)
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what is the iupac name of this compound? h₃c | c=c | | h h ch₂ch₃ optio…
B. cis - 2 - pentene
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15 déterminez la formule chimique des composés formés à partir des subs…
To determine the chemical formula of the compound formed, we use the **cross - multiplication method** (also known as the criss - cross method) for the positive and negative ions.…
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la concentration 19 remplissez le tableau ci-dessous. soluté | masse du…
To solve for the missing values in the table, we use the formulas for concentration: ### 1. For $\boldsymbol{\ce{Na3PO4}}$: #### Step 1: Concentration (g/L) Concentration (g/L) = …
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question 4 (10 points) listen what is the structure of 3-methylcyclohep…
The second option (the one with the 7 - membered ring, a double bond, and a $\ce{CH_3}$ group attached to a carbon that is the 3rd carbon in the cycloheptene numbering)
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21 pour préparer 25,0 ml d’une solution à 3,5 × 10⁻² mol/l, vous utilis…
To prepare the solution, measure \( 8.75 \, \text{mL} \) of the \( 0.10 \, \text{mol/L} \) concentrated solution, transfer it to a \( 25.0 \, \text{mL} \) volumetric flask, and di…
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which elements make up a water molecule? o hydrogen and nitrogen o oxyg…
D. hydrogen and oxygen
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question 19 1 pts chemical substances that change moods and perceptions…
B. psychoactive
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which statements describe molecules? check all that apply. molecules ar…
Molecules are made of two or more atoms. Molecules range in size. Molecules are made of atoms of the same element or different elements.
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graph the following data below. solubility of compound (g solute/100g w…
Solubility of KCl at 40°C is approximately 40 g solute/100g water. Solubility of KClO₃ at 80°C is approximately 42.5 g solute/100g water.
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arrange these stages of moisture retention in the correct order, from w…
Question 1: 2, 4, 3, 1 Question 11: b. Darker soil color Question 12: b. Adding compost or manure
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question 7 (1 point) what does organic matter do to soil structure? a i…
Question 7: A. Improves structure by making more pores Question 8: B. It absorbs and stores water in soil Question 9: B. It has little organic matter and large pores
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why is moisture retention important for soil? o a it holds water for pl…
a. It holds water for plants to use over time b. Plastic a. Pure clay
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question 4 (1 point) why is moisture retention important for soil? a it…
Question 4: C. It holds water for plants to use over time Question 5: A. Plastic Question 6: D. Pure clay
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concept check what is the mass of a 0.75 in³ cube of gold? hint: densit…
$237.694363\ g$
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ischemia would best be described as multiple choice disease of the hear…
D. lack of blood supply to tissue
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the correct pronunciation for ischemic is: multiple choice isk- key-mic…
B. ish - KEY- mic.
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how do prepositional phrases function? read the sentences on the right.…
1. "with his chemistry grade": adverbial phrase modifying an adjective 2. "at the spring carnival": adverbial phrase modifying a verb 3. "behind the firehouse": adjectival phrase …
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click on the butter, watch the animation and look at the before and aft…
Particles' relative positions change. It's a physical change. Evidence: No new substances are formed; only the shape and size of butter pieces change.
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click on the filtered water, watch the animation and look at the before…
This is a physical change because only the appearance changes as particles are removed, not the water's chemical nature.
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1. what is the density of carbon dioxide gas if 0.196 g occupies a volu…
$0.00196\ g/mL$
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silver has two naturally occurring isotopes, ag - 107 (106.905 amu) and…
The percent abundance of Ag - 107 is $51.7\%$ and the percent abundance of Ag - 109 is $48.3\%$.
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question 10 1 pts the figure below shows an atomic bond forming between…
all of the above
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multiple choice question how do lipids differ from other organic compou…
They are insoluble in water
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multiple choice question what class of organic compounds has the chemic…
Carbohydrates
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fill in the blank question a carbohydrate contains atoms of , carbon, a…
oxygen
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still feels unmotivated when learning chemistry and geography and asks …
A. Trello
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multiple choice question molecules with the chemical formula c6h12o6 ar…
D. carbohydrates
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like you, chloe is juggling her time between learning, hobbies, and oth…
B. Notion
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fill in the blank question. the term is the chemical term for a single …
Monosaccharide
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multiple choice question organic compounds, by definition containing bo…
B. hydrogen
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multiple choice the ph scale measures: o the potential of a system to r…
the concentration of hydrogen ions in solution
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question 3 of 3 3 what is one way dry ice is different from regular ice…
A. Dry ice forms at a colder temperature than regular ice
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fill in the blank question by definition, the molecules or atoms that a…
products
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misty magic use the ai reading tool to make sense of tricky words and s…
Dry ice is a result of the sublimation process
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multiple choice question the molecular formula provides information abo…
types of atoms in a molecule
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misty magic use the ai reading tool to make sense of tricky words and s…
B. When dry ice turns into gas
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multiple choice question what is the most abundant compound in the huma…
Water (H₂O)
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two or more atoms that bond together form a(n) _______. o element o mol…
B. molecule
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fill in the blank question. if a compound contains carbon and hydrogen …
organic
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fill in the blank question a value called measures the hydrogen ion con…
pH
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multiple choice question the components of substances that are ______ s…
B. ionically bound
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multiple choice question what is the term for the molecules or atoms th…
C. Products
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6 which quote explains why solids dont take the shape of their containe…
B. "The particles don't move around so much, and they get locked into a rigid structure."
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5 classify each of the following as describing the molecules in a solid…
Solid: vibrating slowly, close together Gas: spread out, moving quickly
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2 what could cause a liquid to become a gas? a raising the liquids temp…
A. Raising the liquid's temperature
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7. how to you maintain your blood ph? 8. an acid is any solution that h…
7. Through buffer systems, respiratory and urinary systems. 8. Hydrogen ions ($H^+$) 9. Hydroxide ions ($OH^-$) 10. Acidic
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select the correct answer from each drop - down menu. read this sonnet,…
1. Spenserian 2. abab bcbc cdcd ee 3. Love is hard to win but endures 4. oak 5. wound
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select the correct answer from each drop - down menu. read this sonnet,…
metaphor
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clue this element is directly above the element with 13 protons the ato…
The clues describe multiple elements. If we consider each clue separately: Boron, Phosphorus, Magnesium, Gallium, Aluminum, Chlorine, Strontium, Arsenic, Tin.
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select the correct answer from each drop - down menu. read this sonnet,…
The sonnet is written in the Spenserian form. The rhyme scheme is abab bcbc cdcd ee. The main idea of the poem is that one needs to be patient when trying to win the love of a lad…
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the atomic number of this element is 49. this element has 2 fewer elect…
1. In 2. As 3. Sn 4. Te 5. Og 6. Sb 7. (No match in options for C) 8. Pb 9. Tl 10. P 11. At 12. Bi 13. Fl 14. Po
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clue,element this element is an alkali metal with 55 protons.,cs this e…
The elements corresponding to the clues are: Cs, Rn, In, As, Sn, Te, Og, Sb, C (not Cs as in table), Pb, Tl, P, At, Bi
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tennessine (ts). this element is directly below the element whose atomi…
The elements corresponding to the statements from top - to - bottom are: Si, Al, Pb, N, Ba, B, Ne, Xe, Ar, Kr, Ga, Ge, Se, S
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this element has one more proton than caesium (cs). this element has 5 …
10: B 11: Ne 12: Xe 13: Ar 14: Kr 15: Ga 16: Ge
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this element has 116 electrons. this element has one more proton than l…
1. Lv 2. Be 3. Mc 4. Si 5. Al 6. Pb 7. N
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this element has 116 electrons. this element has one more proton than l…
The element - symbol pairs are correctly matched as shown in the table. Each row's description correctly corresponds to the element symbol in column B.
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demareas’s employer has started using a new industrial cleaner. even th…
B. No
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which representation conveys that the probability of finding an electro…
D.
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a biochemist carefully measures the molarity of calcium carbonate in 39…
$68.7\ \mu M$
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1st attempt see periodic table see hint select the orbital with the hig…
$n = 5,l = 2$
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how many orbitals are described by each of the below combinations of qu…
5 1
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question (2 points) how many electrons could have the following set of …
(a) 10 (b) 2
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67. what is the name for a biological catalyst? a. enzyme b. radical c.…
67. a. enzyme 68. d. Not watching the reaction as it happens 69. b. Le Chatelier’s principle 70. (production of HCl) c. lower the pressure 70. (production of chlorine gas) a. cool…
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61. when an element loses electrons during a chemical reaction, it has …
61. a. oxidized 62. d. $Ba_{3}N_{2}$ 63. b. $N_{2}+3I_{2} ightarrow2NI_{3}$ 64. b. $H_{3}O^{+}$ 65. acid: 0 - 7; water: 7; base: 7 - 14 66. $CH_{4}+2O_{2} ightarrow CO_{2}+2H_{2}O…
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53. in the following chemical equation, what is the mole ratio of alumi…
53. a. \(2:3\) 54. b. \(6\ mol\) 55. \(CO_2\) 56. b. endothermic 57. b. the octane and other hydrocarbon molecules breaking apart 58. photosynthesis 59. d. All of the above 60. b.…
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question 5 (1 point) build a lithium atom with the following symbol and…
| Name | Lithium - 7 | |--|--| | Number of Protons | 3 | | Number of Neutrons | 4 | | Mass | 7 | | Natural abundance | 92.23 | | Stable? | Stable |
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question 11 (1 point) the weighted average mass for all the isotopes of…
True
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question 10 (1 point) using this periodic table, what is the average at…
6.941
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question 9 (1 point) if you were to calculate an average mass of lithiu…
C. between 6 and 7 but closer to 7
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question 8 (1 point) which of these occurs in nature in a greater abund…
B. Lithium - 7
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question 7 (1 point) which 2 isotopes appear in nature? a lithium-6 b l…
A. Lithium - 6, B. Lithium - 7
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question 6 (1 point) build a lithium atom with the following symbol and…
Blank 1: 8 Blank 2: 3 Blank 3: 5 Blank 4: 8 Blank 5: 0
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question 5 (1 point) build a lithium atom with the following symbol and…
Blank 1: 7 Blank 2: 3 Blank 3: 4 Blank 4: 7 Blank 5: 92.5
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question 4 (1 point) build a lithium atom with the following symbol and…
Blank 1: 6 Blank 2: 3 Blank 3: 3 Blank 4: 6 Blank 5: 7.5
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question 3 (1 point) build a lithium atom with the following symbol and…
Blank 1: 3 Blank 2: 2
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question 2 (1 point) isotopes of the same element have a different _? a…
C. atomic mass
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question 1 (1 point) isotopes are atoms with the same number of protons…
A. neutrons
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analyze and interpret data 1. theme cause and effect based on my observ…
more. Evidence: Water has strong hydrogen - bonding between its molecules which is a type of cohesive force, while rubbing alcohol (isopropyl alcohol) has weaker intermolecular fo…