化學
化學反應、化學計量、分子結構與元素性質。
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4 what is the atomic number of the element? * (1 point) 80 121 201 281
A. 80
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3 how many electrons does the element have? * (1 point) 80 121 201 281
A. 80
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6. white distilled vinegar has a hydrogen ion h⁺ concentration of appro…
C. pH = 2.5
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14. a solution of cuso₄ is made by dissolving.15 g in enough water to m…
$\approx 0.0063\ \text{M}$ (or $6.3\times10^{-3}\ \text{M}$) ### Question 15:
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13. a student mixed 3 moles of kf with enough water to make 740 ml of s…
The molarity of the solution is approximately $\boldsymbol{4.05\space M}$.
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3. what is always written first in the name of an acid to identify it a…
## Question 4: a. hypophosphorous acid b. telluric acid c. selenous acid d. formic acid e. bromous acid ## Question 5: a. $\ce{HFO2}$ b. $\ce{HC7H5O2}$ c. $\ce{HCNO}$ d. $\ce{H2C8…
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calculate the empirical formula of the following compounds: 7. a compou…
$Na_2S$ ### Problem 8:
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how many grams of alcl₃ are produced if 300 g of h₂ are produced? 2al +…
1. 1320 g
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percent composition and empirical formula worksheet calculate the perce…
Let's solve each problem one by one. We'll start with problem 1: calculating the percent composition of \( \text{Pb(NO}_3\text{)}_2 \). ### Problem 1: Percent Composition of \( \t…
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balance the following equations by placing small whole - number coeffic…
$\ce{2Ba + O_{2} -> 2BaO}$ For problem 2 (Synthesis: $\ce{C + S -> CS_{2}}$):
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p7 reactivity trend 9 b. based on the reactivity table, which statement…
D. Potassium (K) is more reactive than Magnesium (Mg)
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7. two students are discussing solubility. student a says, “a polar mol…
Student B is correct because solubility follows the "like dissolves like" principle. Polar water molecules (which rely on dipole-dipole and hydrogen bonding interactions) cannot f…
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4. copper metal and aqueous silver (i) nitrate react to form silver met…
### Question 4 # Explanation: ## Step 1: Write the unbalanced reaction The reactants are copper metal ($\text{Cu}(s)$) and aqueous silver(I) nitrate ($\text{AgNO}_3(aq)$). The pro…
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lewis dot pt lewis dot pt use the periodic table to answer the question…
A. Fluorine 7 valence electrons, Chlorine 7 valence electrons
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post-lab questions: 1. if an element is more electronegative does that …
1. A more electronegative element creates a partial negative charge. This is because it strongly attracts the shared electrons in a bond, concentrating electron density around its…
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properties - metals and nonmetals properties - metals and nonmetals pro…
D. F and Br
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2. how many moles of co₂ are needed to react when do 2.41×10²⁴ molecule…
\( 4.00\ \text{moles} \) ### Question 3
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33. question text unclear a. option a text unclear b. option b text unc…
38. B. Chemical property 39. C. Conductivity 40. C. Extensive 41. B. Malleability 42. B. It lowers the freezing point of water 43. A. Roy J. Plunkett 44. C. Chemical
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24. which property allows graphite in pencils to leave marks on paper? …
24. C. Brittleness 25. A. Ductility 26. C. Reactivity 27. C. They can be observed with the five senses. 28. B. Transparency 29. C. Chemical property 30. B. Intensive property 31. …
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multiple choice questions choose the correct answer for each question. …
17. B. Density 18. D. Mass 19. B. Physical 20. C. Flammability 21. C. Density 22. B. Conductivity 23. D. Volume 24. A. Intensive
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physical and chemical properties worksheet fill in the blank fill in th…
1. Conductivity 2. boiling point 3. physical 4. intensive 5. mass 6. chemical 7. physical 8. chemical 9. Ductility 10. Malleability 11. melting point 12. freezing 13. physical 14.…
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stoichiometry quiz 1. solid potassium reacts with chlorine gas to produ…
Approximately \( 5.50 \, g \) (or \( 5.498 \, g \)) ### Question 2
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rties of four different compounds, ionic compound. his wn in the chart.…
Z
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anna stated that ionic compounds have high melting points and low boili…
A. Strong electrical forces will make ionic compounds have high boiling points
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question 11 of 12 a 30.0 ml sample of pond water contains $1.75 \\times…
equivalent mass = 50.0 g (or 50.05 g) concentration of $\text{CaCO}_3$ = 350 ppm (or 350.3 ppm)
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ese diagrams show two atoms of fluorine and an atom magnesium. which sh…
The correct option is the one where "A magnesium atom donates two electrons to fluorine atoms → Each fluorine atom accepts the electrons → The magnesium atom becomes a +2 ion → Ea…
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naming covalent and ionic compounds worksheet name:____________________…
1. Sulfur dibromide 2. Ammonium sulfate 3. Nitrogen dioxide 4. Lead(IV) carbonate 5. Dinitrogen monoxide 6. Zinc fluoride 7. Carbon tetrachloride 8. Hydrogen selenide 9. Aluminum …
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stoichiometry quiz 1. solid potassium reacts with chlorine gas to produ…
Approximately $\boldsymbol{5.50\ \text{g}}$ (or $5.498\ \text{g}$) ### Question 2
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11) complete the following table to describe three states of matter. th…
### Question 11: Completing the table for three states of matter | | Solid | Liquid | Gas | |----------------|--------------------------------|---------------------------------|--…
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chalk is an ionic compound. which is a property of all ionic com on a c…
a. a high melting point
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water sample was found to have 14 mg caco₃ in a 100.0 ml sample. calcul…
Concentration of $\text{CaCO}_3$ = 8.18 gpg hard
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ionic compounds form crystal structures. molecular structures. pure ele…
A. crystal structures.
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5. the term used to describe anything that has mass and takes up space …
d. matter ### Question 6
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3. which of the following is true of a heterogeneous mixture? a it is n…
c. Different samples may not be exactly alike. ### Question 4
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responder a las preguntas a continuación. dar respuestas con enteros o …
$25\ \text{cm}^3$ ### Parte (b)
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1. there are many different ways to classify matter, but one way is to …
b. mixtures or substances ### Question 2
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question 19 (5 points) \\(^{198}_{}au^+\\) contains ______ electrons, _…
D) 78, 79, 119
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Question was provided via image upload.
b) Group 2
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question 17 (5 points) which amongst the following compounds would you …
C) \(V_2O\)
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question 15 (5 points) saved which of the following acids is not named …
E) HClO₃: chlorous acid
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question 13 (5 points) which of the following is an intensive property?…
Melting point (the option with "Melting point" as the text, which was already selected in the image, but the correct choice is the one labeled "Melting point" among the options: m…
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question 12 (5 points) \\saved which pair of atoms constitutes a pair o…
C) $\boldsymbol{_{26}^{59}X}$ $\boldsymbol{_{26}^{58}X}$
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for each of the following questions, determine whether the compound is …
1) Ionic; Ammonium chloride 2) Covalent; Xenon hexafluoride 3) Covalent; Phosphorus trifluoride 4) Ionic; Iron(III) nitrate 5) Ionic; Titanium(III) bromide 6) Covalent; Krypton di…
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question 6 (5 points) which of the following pairs is incorrect? a) vin…
c) Graphite - compound
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question 5 (5 points) \\ saved which of the following is always a chemi…
Apple rotting
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question 4 (5 points) which of the following mass is the largest? 8.2 ×…
\(8.2 \times 10^{9}\space \mu\text{g}\) (the option with the radio button selected in the original problem, which is correct after unit conversion comparison)
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question 3 (5 points) \\(\\boldsymbol{\\downarrow}\\) saved which of th…
The incorrect formula - name combination is \(Na_3PO_3\): sodium phosphate (the option with this combination).
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information page (click the link to access the information page. the in…
c) Copper(I) phosphide
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question 1 (5 points) an element, y, has three isotopes. isotope (^{232…
233.59 amu
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step 1 – sketch the lewis structure from the molecular formula, drawing…
All entries in the table are verified as correct: 1. For $\ce{CH4}$: Lewis structure (109.5° bond angle), electron geometry = tetrahedral, molecular geometry = tetrahedral, nonpol…
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the rapid movement of gases molecules can be explained because gases ha…
D. small, little
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the molecules of a substance are moving rapidly in a container. the mol…
B. gas
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open-ended question what does the law of conservation of mass state?
The law of conservation of mass states that in a closed system, the total mass of substances before a chemical reaction (reactants) is equal to the total mass of substances after …
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a potassium iodide compound is represented by which formula? a k₂i b k₂…
C. \( KI \) (assuming option C is \( KI \); adjust based on exact option labels, but the correct formula for potassium iodide is \( KI \))
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isotopes of an element differ in the composition of the nucleus. the va…
B. neutrons, mass number
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most elements on the periodic table are a gases b metals c nonmetals d …
B. metals
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a positively charged ion will bond with a a negatively charged ion. b a…
A. a negatively charged ion.
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how many grams of o₂ are required to produce 358.5 grams of zno? 2zn+o₂…
70.4 g
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consider this row in the periodic table of elements. evaluate which ele…
A. lithium and beryllium
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based on the mole ratios of the substances in a chemical reaction shown…
D. \( 3A + 2B ightarrow C \) (Note: Assuming the last option is D as per the order, with the equation \( 3A + 2B ightarrow C \))
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write the formula for the following compounds: | compound | formula | |…
### Formula Writing: 1. Calcium chloride: $\text{CaCl}_2$ 2. Carbon trioxide: $\text{CO}_3$ 3. Magnesium oxide: $\text{MgO}$ 4. Dinitrogen pentoxide: $\text{N}_2\text{O}_5$ 5. Alu…
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the unbalanced chemical equation for the reaction of magnesium nitrate …
1:3
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check out the picture of the periodic table of elements. follow the arr…
C. The elements change from metals to nonmetals.
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the unbalanced chemical equation for the decomposition of aluminum oxid…
40 moles (corresponding to the option "40 moles")
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which statement accurately describes covalent bonds? a covalent bonds a…
B. Covalent bonds are typical of carbon compounds.
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using the periodic table, elaborate the difference between the number o…
D. The number of electrons are the same for all isotopes of an element - so both oxygen - 16 and oxygen - 18 contain 8 electrons.
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do these molecules make up the same substance? yes no
no
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and one oxygen atom. what is the chemical formula for the substance com…
$C_2H_4O$ (corresponding to the option with formula $C_2H_4O$)
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first, select the model of a molecule composed of two carbon atoms and …
The model labeled "ethane" (the first molecular model with two carbon atoms and six hydrogen atoms). ### Part 2: Select the chemical formula
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select all the ways in which two substances can be different two substa…
All three options (the ones stating "Two substances can be composed of the same chemical elements, but the substances can have crystal structures with atoms that are arranged diff…
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1) complete the statement. 2) these molecules make up 3) the same subst…
different substances
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____ are different forms of a single element. a atoms b elements c ions…
D. Isotopes
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the periodic table organizes elements according to increasing a atomic …
C. atomic number
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select the model of a molecule composed of one carbon atom, two hydroge…
The first model (labeled "formic acid") ### Part 2: Determining the chemical formula
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what is the chemical formula for aluminum nitride? a al₃ b aln₃ c al₃n₃…
D. AlN
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the rapid movement of gases molecules can be explained because gases ha…
D. small, little
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4) first, select the model of a molecule composed of two carbon atoms a…
Left model (labeled "ethylene" or "ethene") ### Part 2: Chemical formula for 10 ethylene molecules
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given the following mystery ions, \\(x^{3+}\\) \\(m^{2-}\\) \\(q^{2+}\\…
A. $Q_2M_2$
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an atom that has lost or gained electrons is known as an ion. which com…
C. \( \text{KBr} \)
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a group on the periodic table is best described as a ______. a column b…
A. column
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question 5 mechanical weathering process that occurs when water repeate…
A. frost wedging
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weathering pre and post learning quiz started: feb 5 at 7:47am quiz ins…
A. exfoliation
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question 1 20 pts process by which rocks and minerals undergo changes i…
A. chemical weathering
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why are biogeochemical cycles important? earth is a closed system. that…
First drop - down: stays the same (or remains constant) Second drop - down: recycle (or reuse, circulate)
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question 5 of 10 to measure how much stuff is in a specified volume of …
density
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when classifying matter, it is helpful to organize your information in …
1. element 2. compound 3. suspension 4. solution 5. colloid
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directions: match the terms in column ii with the definitions in column…
## Matching Section 1. f. suspension 2. h. homogeneous mixture 3. e. element 4. d. mixture 5. a. Tyndall effect 6. b. colloid 7. c. heterogeneous mixture 8. g. solution 9. i. comp…
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question 2 points 2 identify the grammatically correct sentence. the un…
B. The university offers many majors in engineering, such as chemical, industrial, and electrical engineering.
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temperature and solubility background knowledge it is easier to dissolv…
Yes, there is a relationship. As temperature increases (from \(20^{\circ}\text{C}\) to \(60^{\circ}\text{C}\)), the solubility of table salt (amount dissolved per jug) increases (…
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6. fill in the missing information in the table below. note: all soluti…
To solve this, we need the solubility values of each solute at the given temperatures (from solubility tables): ### 1. Solution: A solution that contains 70 g of $\ce{NaNO3}$ at $…
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6. fill in the missing information in the table below. note: all soluti…
To solve this, we need the solubility data (in g per 100 mL water) for each solute at the given temperatures. Let's recall typical solubility values (from solubility curves): ### …
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using the above solubility curve, answer the given questions. 1. which …
\(KClO_3\) (or other correct salt based on the curve, but \(KClO_3\) is a common answer here) ### Question 2
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draw simple graphs that show the relationship between temperature and s…
### 1. Temperature vs. Solubility (Liquid and Solid Solutes) #### Explanation: For most solid and liquid solutes, solubility generally increases with an increase in temperature. W…
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barometric pressure (mmhg) 770.0 observations bubble formation. volume …
To find the ideal gas constant \( R \), we use the ideal gas law \( PV = nRT \), where: - \( P = 1.013 \, \text{atm} \) (pressure of \( \text{H}_2 \)), - \( V = 0.0190 \, \text{L}…
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barometric pressure (mmhg) observations bubble formation. volume of hyd…
To solve for the moles of hydrogen gas produced, we use the ideal gas law, \( PV = nRT \), where: - \( P \) = pressure of hydrogen gas (atm), - \( V \) = volume of hydrogen gas (L…
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question 10 of 14 each image depicts what happens when different types …
- Strong electrolyte: The middle image (only separate blue spheres and gray charged spheres, no intact paired molecules) - Weak electrolyte: The bottom image (a mix of intact pair…
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moment of truth think you know everything there is to know about vaping…
RIGHT (the option "RIGHT" is the correct choice as the statement "E - cig waste contains chemicals that can burn or explode" is true.)
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question 4 of 14 write the balanced chemical equation for the reaction …
$\boldsymbol{2\text{NO} + \text{O}_2 = 2\text{NO}_2}$
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11) choose the correct answer. global warming is an example of ____. ra…
C. climate change ### Question 12
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3) choose the correct answer. ____ occurs when pollutants from the smok…
C. Acid rain ### Question 4