化学
化学反応、化学量論、分子構造、元素の性質。
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determine the amount in grams of kcl that exists in 20.3 g of a solutio…
$0.231\ \text{g KCl}$ (The filled setup would be: Starting amount: $20.3$ $\text{g solution}$ Multiplied by $\frac{1.14\ \text{g KCl}}{100\ \text{g solution}}$)
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the purpose of an electric motor is to convert ______. choose 1 answer:…
A. electrical energy into kinetic energy
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how many grams of a solution that is 5.20 % sucrose by mass are needed …
346 g solution
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what is the molarity of potassium ions in a 0.122 m k₂cro₄ solution?
$0.244\ \text{M } K^+$
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here is the reaction you drew for protonation of methanol with an acid.…
1. Protonation of methanol first occurs: $CH_3OH + H^+ ightarrow CH_3OH_2^+$ 2. A second methanol molecule (as nucleophile) attacks the oxonium ion, leading to elimination of $H_2…
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5. which process is necessary to the formation of clouds? (options: war…
(Assuming the correct option is related to condensation, e.g., if options are A. evaporation, B. precipitation, C. condensation, D. transpiration, then) C. condensation ### Questi…
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in the boxes, draw the structures, including all bonds, lone pairs and …
Left box structure: ``` H | H - C - O:⁻ | H ``` (Plus a separate $\text{H}^+$; oxygen has 3 lone pairs, negative charge) Right box structure: ``` H | H - C⁺ - O - H | H ``` (Oxyge…
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which is a nonpoint source of pollution? ○ tourists throw trash into th…
C. Rain contains chemicals that seep into the ground.
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a particular antibiotic kills 99% of a bacterial population. what will …
## Part E Over time, the antibiotic will become less effective at killing the bacteria ## Part F The use of any chemical that kills bacteria can eventually lead to resistance to t…
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draw a skeletal (\line\) structure of this molecule: $\\ce{ch3 - c(=o) …
The skeletal (line) structure of the molecule is: ``` CH₃ | O | O ║ | ║ C - C - C - C - CH₃ | CH - CH₃ | CH₃ ``` (Or in a more compact and standard drawing: ``` CH3 | O | O || | |…
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how many different molecules are drawn below? (with molecular structure…
4
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which statement best explains the difference between polar and nonpolar…
D. Polar covalent bonds share electrons unequally, while nonpolar covalent bonds share electrons equally.
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which option contains an example of a polyatomic ion? (1 point) ○ mgcl …
C. \( \text{KNO}_3 \)
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matching careers with clusters: part 3 match each job example with its …
Jake is a Flight Attendant. → Transportation and Logistics Israel is a Cashier. → Marketing, Sales, and Service Deb is a Video Game Designer. → Information Technology Rakhee is an…
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solve the problems. show your work and use significant figures. round a…
5) $\boldsymbol{9.17 \times 10^{21}}$ atoms 6) $\boldsymbol{1.67 \times 10^{23}}$ molecules
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3) what is the molar mass of na₂so₄? 4) what is the mass, in grams, of …
3) The molar mass of $\text{Na}_2\text{SO}_4$ is $142\ \text{g/mol}$ 4) The mass of 2.0 moles of $\text{CO}_2$ gas is $88\ \text{g}$
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solve the stoichiometry problems. show your work and use significant fi…
1) $32.10\ \text{g/mol}$ 2) $233.99\ \text{g/mol}$
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the molar mass of 1 mole of silver nitrate is 169.88 g/mol. step 4: div…
$\boldsymbol{6.02 \times 10^{23}}$ (Option B)
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3) choose the best answer. a student compared a mole of water (h₂o) mol…
- Both samples have the same number of hydrogen atoms. - Both samples have an equal number of molecules.
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1) choose the best answer. mole ratios are obtained from the ____ in a …
1. coefficients 2. amount of particles
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organic chemistry ii electrophilic aromatic substitution (synthesis of …
The multi-step synthesis of 4-nitrobenzoic acid from benzene is: 1. Friedel-Crafts alkylation of benzene to toluene 2. Nitration of toluene to p-nitrotoluene 3. Oxidation of p-nit…
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long answer questions q.1(ex. q. 1) what are carbohydrates? how are mon…
### Q.1: 1. **Carbohydrates**: Macromolecules defined as polyhydroxy aldehydes or ketones, with the general formula $\text{C}_n(\text{H}_2\text{O})_n$. They are classified into: -…
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how would the electron configuration of nitrogen change to make a stabl…
It would gain three electrons.
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how does rb bond with other elements? (1 point) ○ rb gains two electron…
C. Rb loses an electron.
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which of the following combination of elements is the most reactive? (1…
Cs and Br
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which feature is unique to group 18 nonmetals? (1 point) ○ they follow …
C. They are very nonreactive.
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how do nonmetals tend to form bonds? (1 point) by losing protons by gai…
C. by gaining electrons
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why does the reactivity of metals increase from right to left on the pe…
C. Metals on the right have more protons, causing valence electrons to be held more strongly.
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which statement describes the bonds in iron sulfate (feso₄)? (1 point) …
A. Fe and S are ionically bonded, while S and O are covalently bonded
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this image shows electronegativities of elements on the periodic table.…
A. fluorine (F)
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determine the quantity of hydrogen atoms in 0.1488 g of phosphoric acid…
$2.743 \times 10^{21}$ atoms H
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determine the quantity of atoms of vanadium in 1.28 grams of vanadium. …
$1.51 \times 10^{22}$ atoms of vanadium Filled setup for the tool: Starting amount: $1.28\ \text{g V}$ Conversion factor: $\frac{1\ \text{mol V}}{50.94\ \text{g V}} \times \frac{6…
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identifying health science careers what are examples of health science …
- Registered Nurse - Emergency Medical Technician - Dentist - Surgeon - Medical Assistant
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determine the quantity of moles of propylene (c₃h₆) in 25.0 g of the su…
$0.594\ \text{mol}\ \text{C}_3\text{H}_6$ (Note: Filling the interactive template: Starting amount: $25.0$, unit: $\text{g}\ \text{C}_3\text{H}_6$ Conversion factor numerator: $1$…
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question 14 of 26 determine the quantity of moles in 4.21×10²³ formula …
0.699 mol CaCl₂ ### Filled-in setup breakdown: Starting amount: $4.21 \times 10^{23}$ formula units CaCl₂ Conversion factor: $\frac{1 \, \text{mol CaCl}_2}{6.022 \times 10^{23} \,…
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determine the mass in grams of 1.6 × 10⁻³ mol glucose, c₆h₁₂o₆. the int…
$0.29\ \text{g}$ (For the interactive template: - Starting amount box: $1.6 \times 10^{-3}$ and $\text{mol } C_6H_{12}O_6$ - Conversion factor numerator: $180.18$ and $\text{g } C…
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question 13 of 26 determine the mass in grams of 1.6 × 10⁻³ mol glucose…
$0.29\ \text{g}\ \text{C}_6\text{H}_{12}\text{O}_6$ (Note: Filled into the structure: Starting amount box: $1.6 \times 10^{-3}\ \text{mol}\ \text{C}_6\text{H}_{12}\text{O}_6$ Frac…
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determine the mass, in grams, that are in 5.32 × 10²² molecules of co₂?…
$3.89 \text{ g CO}_2$ (The filled setup is: Starting amount: $5.32 \times 10^{22}$ molecules $\text{CO}_2$ Conversion factor: $\frac{1 \text{ mol CO}_2}{6.022 \times 10^{23} \text…
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what type of matter is shown in this particle diagram? options: element…
Mixture of Elements and Compounds
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question 12 (4 points) corrosive indicates: - that the material can deg…
That contact destroys living tissue as well as equipment
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general guidelines for preventing accidents include: know where the saf…
All of the above
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question 6 (4 points) saved the cas registry number is is usually fatal…
a unique identifying number for each chemical
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draw the lewis structure for ethylamine (c₂h₇n). ethylamine molecules h…
The Lewis structure of ethylamine (\( C_2H_7N \)) is \( \boldsymbol{\text{H}_3\text{C} - \text{CH}_2 - \text{NH}_2} \) with a lone pair (two non - bonding electrons) on the nitrog…
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a substance that helps maintain a constant ph is best described as sele…
a buffer
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a buffer should be able to stabilize ph select increase ph act as a neu…
stabilize pH
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question 4 5 pts a solution has a ph of 4 before a buffer is added. the…
remain the same
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which process is defined as breaking down rocks into smaller pieces wit…
D. mechanical weathering
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adding select select to a solution will decrease the ph. select neutral…
hydrogen ions
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which is a common use of minerals? ○ pasta ○ toothpaste ○ applesauce ○ …
B. toothpaste
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which process is responsible for changing the composition of rock? ○ er…
chemical weathering
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this is mohs hardness scale. | mineral | hardness | |-----------|------…
corundum, quartz, calcite, gypsum
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predicting human impact on freshwater sources page 1 page 2 acid rain i…
- produce energy using water power - use electricity or energy-saving products - create technology to capture sulfur dioxide
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how do acids and bases affect the quality of freshwater sources? ○ acid…
Acids lower the pH of freshwater and bases raise the pH of freshwater.
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exercice n°8 on dissout 120cm³ de gaz hcl dans une quantité d’eau disti…
Désolé, le texte fourni n'est pas valide. Veuillez fournir plus de détails ou clarifier votre question afin que je puisse vous aider mieux.
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physique chimie 3ème 1) écrire l’équation bilan de la réaction qui s’es…
Désolé, le texte fourni n'est pas valide. Il manque des informations essentielles (comme la nature du gaz, sa masse, les conditions de la réaction...) pour répondre aux questions.…
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what are the coefficients, reading left to right, when the chemical equ…
1, 3, 1, 3
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drag an oval over the format below that symbolizes these formulas: (mol…
$3\text{CH}_2\text{O}$ (the middle option)
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check the box under each molecule in the table below that is an isomer …
The box under the top - left molecule (the one with two -OH groups and a double bond, \(\ce{HO - CH2 - CH2 - CH=CH - OH}\) - like structure) should be checked. Also, if we conside…
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write the electron configuration of an atom of the element highlighted …
$\boldsymbol{[Ar] 4s^2 3d^8}$ (or if the element is Fe, it would be $[Ar] 4s^2 3d^6$, but based on the position in the periodic table outline, the correct electron configuration i…
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chemical equations are balanced when what quantity or quantities are th…
- The sum of masses of all substances involved. - The number of atoms of each kind.
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in the lab, jose has two solutions that contain alcohol and is mixing t…
700
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type the correct formula for the compounds formed between the following…
\(Na_2CO_3\)
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question 1 of 10 read these lines from \one art\ by elizabeth bishop: t…
A. aba
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1. try marking the rhyme scheme in gwendolyn brooks’s “the sonnet-balla…
1. The rhyme scheme of *the sonnet-ballad* is **ABAB CDCD EFEF GG**, with occasional slant/near rhymes. 2. Notable traits: Consistent Shakespearean sonnet structure paired with sl…
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watershed. harmful algal blooms are characterized by a rapid increase i…
- Algae population will increase. - Trout population will decrease. - Minnow population will decrease.
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which phrase refers to the repeating pattern of a mineral’s particles? …
B. crystal structure
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which of the following elements has the lowest electronegativity value?…
d. Si
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in general, as an approximation, elements with an electronegativity val…
b. Nonmetals
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which of the following explains why electronegativity decreases from ri…
b. The number of protons decreases, so the nucleus is less positively charged
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p, al, cl, si, na, s, mg which of the elements above is the most electr…
Cl (or Chlorine)
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group 13 group 14 group 15 group 16 group 17 b - 5 c - 6 n - 7 o - 8 f …
F (or Fluorine, or 9)
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question 3 1 pts what is the molarity when 24 grams of lioh is added to…
C. 5 M ### Question 4
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question 1 1 mole of water, 3 moles of methanol and 5 moles of ethanol …
0.33 ### Question 2
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6. a 0.750 l aqueous solution contains 90.0 g of ethanol, c₂h₅oh. calcu…
\( 2.60 \, \text{mol/L} \)
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question 7 1 pts what is the % yield if 20 grams of hydrogen is reacted…
25% (Option: 25 %) ### Question 8
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question 5 1 pts an organic synthesis to make the pain reliever acetomi…
75% (Option D: 75%) ### Question 6
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question 3 1 pts consider the combustion of ethane reaction below for t…
8 (the option with 8) ### Question 4
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question 1 1 pts consider the combustion of hydrogen for the next two q…
Hydrogen and 10 moles water produced. ### Question 2
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question 7 1 pts what is the number of nitrogen molecules that reacted …
\(1\times 10^{10}\) (corresponding to the option "1 × 10¹⁰") ### Question 8
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question 3 1 pts the difference between doing compositional stoichiomet…
A. the use of stoichiometric mole ratios (Note: Assuming the first option is A, as per the order. If options had labels, use the correct label. Here, the first option is the corre…
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question 1 1 pts what is the law that ensures that chemical reactions a…
D. The law of conservation of matter ### Question 2
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solubility curves of several ionic compounds 3. use the solubility curv…
s: a. Unsaturated b. Unsaturated c. Unsaturated
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question 23 of 37 estimate the pkₐ values for the functional group clas…
1. Ethanol: 15 2. Acetic acid: 5 3. Ethanammonium: 10 4. Isobutane: 50 5. 3-methyl-1-butyne: 25 6. Diethylamine: 35
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consider the reaction and indicate which reactant in the lewis acid and…
- $\text{BF}_3$ is the Lewis acid. - $\text{CH}_3\text{OH}$ is the Lewis base.
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consider the reaction and indicate which reactant is the lewis acid and…
$\text{FeCl}_3$ is the Lewis acid. $\text{CH}_3\text{COCl}$ is the Lewis base.
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organic chemistry loudon | parise seventh edition label each of the rea…
$\text{CH}_3\text{OCH}_3$ is a: Lewis base $\text{BF}_3$ is a: Lewis acid
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compound c: the indicated carbon in compound c is ○ electrophilic. ○ nu…
Compound C: electrophilic. Compound D: neither electrophilic nor nucleophilic.
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question 4 of 37 identify the conjugate acid for each base. conjugate a…
conjugate acid of HS⁻: $\text{H}_2\text{S}$ conjugate acid of PO₄³⁻: $\text{HPO}_4^{2-}$ conjugate acid of NH₃: $\text{NH}_4^+$
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organic chemistry maxwell presented by macmillan learning consider the …
## Acid: $\text{HC≡CH}$, $\text{CH}_3\text{CH}_2\text{OH}$ ## Base: $\text{CH}_3\text{CH}_2\text{O}^-$, $\text{HC≡C}^-$
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classify each reactant and product in the reaction as an acid or base a…
## Acid: $\text{HNO}_3$, $\text{(CH}_3\text{)}_3\text{COH}$ ## Base: $\text{(CH}_3\text{)}_3\text{CO}^-$, $\text{NO}_3^-$
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question 33 of 37 for the list of compounds, rank the compounds in stre…
Weakest: $\ce{NH3}$ $\ce{PH3}$ $\ce{AsH3}$ Strongest: $\ce{SbH3}$
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question 36 of 47 for the list of alcohols, rank the alcohols in streng…
Weakest → $\text{CH}_3\text{OH}$ → $\text{FCH}_2\text{OH}$ → $\text{F}_2\text{CHOH}$ → $\text{F}_3\text{COH}$ → Strongest
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for the list of compounds, rank the compounds in strength from weakest …
Weakest: $\text{H}_4\text{Si}$ $\text{H}_3\text{P}$ $\text{H}_2\text{S}$ Strongest: $\text{HCl}$
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part b: mass-to-mole 6. how many moles are in 36.04 g of water (h2o)? 7…
\(2\space mol\) ### Question 7:
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question 10 of 10 read the lines: that woman’s days were spent in ignor…
D. abcb
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question 3 of 10 which is the best definition of a rhyme scheme? a. rhy…
C. Rhymes used in a repeating pattern
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3. write the rhyme scheme for the following four lines from emily bront…
ABCB
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3. write the rhyme scheme for the following four lines from emily bront…
ABAB
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question 12 2 pts which of the following factors influence how soils de…
- living things that add organic matter to soils, and remove nutrients - water and rainfall - this weathers parent material and transports soil particles - rock parent material th…
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classify the following as a heterogeneous mixture (suspension), homogen…
homogeneous mixture (solution)