Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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32) ions can be formed from atoms by losing or gaining electrons. selec…
13 protons, 14 neutrons, and 10 electrons
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1) the element with atomic number 53 always contains (3pts) □ 53 neutro…
53 protons.
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30) the species shown below which has 24 neutrons is (3pts) \\(_{24}^{5…
$\boldsymbol{^{45}_{21}Sc}$
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28) which pair of formulas illustrates the law of multiple proportions?…
$\boldsymbol{\text{CuO and CuO}_2}$
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27) the specific heat of zinc is 0.388 j/g°c. a 700.0 g sample of zinc …
$\square$ 43.6 $^\circ$C
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26) the specific heat of aluminium is 0.900 j/g°c. how much energy is r…
$\boldsymbol{877\ \text{J}}$ (Option: $\boldsymbol{\square\ 877\ J}$)
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23) 3.17 g of sodium combines with chlorine to form 8.00 g of sodium ch…
4.83 g ---
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21) which of the following is chemical property of iodine? (3pts) □ blu…
$\square$ blue black color $\square$ shiny crystals $\square$ sharp odor $\checkmark$ corrosive vapor --- ### Question 22
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20) which element is not reactive? (3pts) fluorene sodium argon boron
□ Argon
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chemistry 1 ionic nomenclature 1 complete the table following the examp…
a. Aluminum chloride b. Magnesium sulfide c. Aluminum nitride d. Sodium sulfide e. Calcium fluoride --- ### 3. Completed Table (Ionic Compound Formulas & Names)
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18) which element forms diatomic molecules? (3pts) □ carbon □ bromine □…
18) bromine 19) 21
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17) the alkali metals are in group ____. (3pts) □ 1a □ 2a □ 5a □ 7a
$\boldsymbol{\square}$ 1A
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16) which would you classify as a semiconductor? (3pts) diamond silicon…
□ Silicon
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14) the density of copper is 8.96 g/ml. the volume of 12 mg of copper i…
14) 0.0013 mL 15) 175 g
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12) a metal alloy melts at 25°c. what is this temperature in °f? (3pts)…
12) $\boldsymbol{77\ \degree\text{F}}$ 13) $\boldsymbol{5.11\ \text{g/mL}}$
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2nh₃(g) + 3o₂(g) + ch₄(g) → 2hcn(g) + 6h₂o(g) considering the thermodyn…
A
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2nh₃(g) + 3o₂(g) + ch₄(g) → 2hcn(g) + 6h₂o(g) calculate the gibbs free …
\(-1107\)
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$$ce{p_{4}o_{10}(s) + 6h_{2}o(l) -> 4h_{3}po_{4}(aq)}$$considering the …
D
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6) which of the following is an example of a homogeneous mixture? (3pts…
$\square$ stainless steel
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p₄o₁₀(s) + 6h₂o(l) → 4h₃po₄(aq) calculate the gibbs free energy change …
-356
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4) your lab instructor gives you a red solid and tells you that it is a…
The solid has a fixed composition by mass.
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which statement is true for the reaction below?\\(\\ce{n2o4(g) -> 2no2(…
D. The reaction will occur only at high temperatures.
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3) the two types of pure substances are (3pts) compounds and elements. …
☑ compounds and elements.
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nameangelina emiren 2/2/26 write equations from verbal descriptions 1. …
\(y = \frac{1}{9}f\) ### Problem 2
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1) the distinction between law and theory as used by scientists is (3pt…
1. a law tells what happens, and a theory tells us why it happens. 2. phosphoric acid, $H_3PO_4$.
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calculate the standard entropy change for the combustion of propane, a …
-373
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which reaction results in a decrease in the entropy of the system? h₂o(…
A. \( \ce{H2O(g) -> H2O(l)} \)
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which reaction results in a negative δs? 2hgo(s)→2hg(l) + o₂(g) nacl(s)…
\(\boldsymbol{\text{H}_2\text{O}(l) ightarrow \text{H}_2\text{O}(s)}\) (the third option)
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calculate the standard reaction enthalpy for the reaction between no an…
-199
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calculate the standard enthalpy of formation, $delta h_{f}^{circ}$, of …
+50.8
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which of the reactions below is a formation reaction? ½n₂(g) + o₃(g) → …
6C(s, graphite) + 6H₂(g) + 3O₂(g) → C₆H₁₂O₆(s) (the fourth option)
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which of these could be part of the reactants in a formation reaction? …
\( \boldsymbol{P(s)} \) (since it is an element in its standard state, suitable as a reactant in a formation reaction)
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calculate the enthalpy for this reaction. h₂o + c → co + h₂ use the fol…
+131.5
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calculate the enthalpy for this reaction. mg + \\frac{1}{2}o_2 \ ightar…
\(-643\)
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show what you know in the boxes below, sketch out how each type of reac…
### Endothermic Graph: - Left dashed line: Reactants (lower energy) - Right dashed line: Products (higher energy) - Reaction line: Curved line starting at reactants, rising to a s…
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science 10 name: practice drawing the following compounds mgo naf lif l…
1. **NaF**: - Sodium ion (Na⁺): Nucleus with 11p, 11n; 2 electron shells with 2 and 8 electrons, labeled +1. - Fluoride ion (F⁻): Nucleus with 9p, 10n; 2 electron shells with 2 an…
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the mole and avogadros number name one mole of a substance contains avo…
The number of molecules in 15 moles is $9.03\times10^{24}$ ### For question 5 (0.35 mole):
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13. base your answer(s) to the following question(s) on the information…
1. Reacción de descomposición (térmica) 2. Reacción de síntesis (o reacción de combinación; también es una reacción de oxidación-reducción, pero el tipo principal por la estructur…
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8. given the balanced equation representing a reaction: zn(s) + h₂so₄(a…
8. C. single replacement 9. A. single replacement and decomposition 10. A. synthesis 11. A. single replacement 12. C. $H_2SO_4 + Mg ightarrow H_2 + MgSO_4$ 13. Decomposition react…
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a. single replacement and decomposition b. single replacement and doubl…
- Pregunta (In which type of chemical reaction...): A. synthesis - Pregunta 13: Decomposition reaction (descomposición) - Pregunta 14: Synthesis reaction (síntesis)
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4. 1. given the balanced equation: agno₃(ad) + nacl(ad) → nano₃(ad) + a…
1. D. double replacement 2. B. decomposition
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balancing equations - problems instructions: balance the chemical equat…
1. $1\text{CH}_2\text{O} + 1\text{H}_2 ightarrow 1\text{CH}_3\text{OH}$ 2. $2\text{NH}_3 ightarrow 1\text{N}_2 + 3\text{H}_2$ 3. $1\text{C}_2\text{H}_6 ightarrow 1\text{C}_2\text{…
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1. given the balanced equation: \\(\\ce{agno_{3}(aq) + nacl(aq) \ ighta…
1. D. double replacement 2. B. decomposition 3. C. decomposition, double replacement, and synthesis 4. D. synthesis 5. A. $\text{CaCO}_3(\text{s}) ightarrow \text{CaO}(\text{s}) +…
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4. 15 moles 5. 0.35 mole how many moles are in the number of molecules …
To solve for the number of moles from the number of molecules, we use the formula: $\text{Moles} = \frac{\text{Number of Molecules}}{6.02 \times 10^{23}\ \text{molecules/mol}}$ (A…
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0 ch₂o + 0 h₂ → 0 ch₃oh
$\boldsymbol{1\ \text{CH}_2\text{O} + 1\ \text{H}_2 ightarrow 1\ \text{CH}_3\text{OH}}$
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question #12 fertilizer runoff containing nitrogen and phosphorous flow…
C. The populations of fish in the lake will decrease.
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at the bottom of the page, choose the separate water option. 9) in the …
1. Product 2. Reactant 3. 2, 2, 1 (for $\text{H}_2\text{O}$, $\text{H}_2$, $\text{O}_2$ respectively) 4. (Left box: 2 molecules of $\text{H}_2\text{O}$ (each with 1 O and 2 H atom…
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1pt nico combines lemon juice, ice, and sugar. what is the result? drag…
First blank: sugar Second blank: lemon juice Third blank: solution
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balancing equations - phet simulator instructions: open the balancing c…
1. **For reactant/product identification**: - $\text{N}_2$: Reactant - $\text{H}_2$: Reactant - $\text{NH}_3$: Product 2. Balanced coefficients: $\boldsymbol{1}$ $\text{N}_2 + \bo…
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sugar and salt are solids, but when they are mixed thoroughly into wate…
B. The water causes the salt and sugar to dissolve and form a solution.
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a student adds 35 grams of sand to a container that holds 100 grams of …
A. When the water is weighed again, it will weigh 85 grams. D. If the water and wet sand are weighed together, the total weight will be 150 grams.
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a student is conducting an investigation to compare the weight of objec…
C. 120 grams
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4. in it seems like matter is lost during a chemical reaction? a. b. ma…
4. C. some matter becomes a gas and spreads into the air 5. D. Matter is not created or destroyed during reactions
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1. wh... chemical reaction? * a. when a substance melts b. when two or …
1. B. When two or more substances form a new substance 2. C. Bubbles forming when baking soda and vinegar are mixed 3. C. It stays the same 4. It may seem like matter is lost if a…
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if 7.51 moles co₂ are emitted, how many grams of octane fuel (c₈h₁₈) do…
107 grams of octane fuel ($\text{C}_8\text{H}_{18}$) need to be burned.
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part ii: give me five directions: give two facts and three examples for…
## Chemical reaction 1. Fact: Rearranges atomic bonds 2. Fact: Produces new substances 3. Example: Rusting of iron ($4\text{Fe} + 3\text{O}_2 ightarrow 2\text{Fe}_2\text{O}_3$) 4.…
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$$i_2 (g) + cl_2 (g) \ ightarrow 2icl (l)$$ how many moles of iodine ar…
$4.39 \text{ mol } \text{I}_2$
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what is the molar mass of li₂o?
The molar mass of $\ce{Li2O}$ is approximately $29.88\ g/mol$ (or can be rounded to $30.0\ g/mol$ depending on significant figures).
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9. what mass of nacl is needed to prepare 125ml of a 2.5m solution? (re…
$18.28125\ \text{g}$ (or rounded to $18.3\ \text{g}$)
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the substance in which something is dissolved to make a solution is cal…
c) A solvent
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the substance that is dissolved in a mixture is called? a) a suspension…
d) A solute
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3.) what is the chemical formula for iron (iii) oxide? (1 point) fe₂o₃ …
A. $Fe_2O_3$
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2.) what is the chemcial formula for potassium sulfide? (1 point)\\(\\b…
A. \(K_2S\)
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1.) what is the chemical formula with mg⁺² and cl⁻¹? (1 point) ○ mg₁cl₂…
D. \( \text{MgCl}_2 \)
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goal: use your research from your questions to build a paragraph (jan 2…
Temperature directly impacts the rate and size of crystal growth. First, the solubility of most solids increases with temperature, so hot water can hold far more borax than cold w…
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1.6: temperature conversion; pictographs, bar graphs, and circle score:…
$365$ °F
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1.6: temperature conversion; pictographs, bar graphs, and circle graphs…
$-90$
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illustrate a chart that displays 5 chemical and physical changes. you c…
| Physical Changes (No New Substance) | Chemical Changes (New Substance Formed) | |--------------------------------------|------------------------------------------| | 1. Melting …
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now we need to prepare a buffer that has a ph of 7.4. we need this spec…
c) By mixing weak acid with its conjugate base and then adjusting the pH with strong base
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the combustion of 4.00 grams of milk in a bomb calorimeter resulted in …
\(248\) (or approximately \(247.9\)) \(J/^{\circ}C\) (If we calculate more precisely \(\frac{843}{3.4}=247.941176\cdots\), so we can present it as \(248\) or \(247.9\) depending o…
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hcl + naoh → nacl + h₂o 25.0 ml of 1.00 m hcl is added to 75.0 ml of 1.…
-148.4 (or -148 if rounded, but the precise calculation gives -148.4)
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2naoh + h₂so₄ → 2h₂o + na₂so₄ 50.0 ml of 0.50 m h₂so₄ is added to 60.0 …
\(-24.33\) (or more precisely, if we calculate \(\frac{-584\space J}{0.024\space mol}=\frac{-0.584\space kJ}{0.024\space mol}\approx - 24.33\space kJ/mol\))
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select the correct answer. which pair of verbs correctly completes this…
B. busqué, almorcé
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draw a skeletal (\line\) structure of this molecule: ch₃—ch≡ch—ch≡ch—ch…
The skeletal (line) structure of the molecule \( \text{CH}_3 - \text{CH} \equiv \text{CH} - \text{CH} \equiv \text{CH} - \text{CH}_3 \) is \( \text{CH}_3 - \ce{C\equiv C - C\equiv…
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question 15 0.5 pts when the chemical bonds of the nutrients in foods w…
Question 15: Energy is released Question 16: 0
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question 13 0.5 pts if a serving of cereal contains 14% of the daily va…
Question 13: True Question 14: energy
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question 7 0.5 pts which of the following numbers is within the accepta…
Question 7: 56% Question 8: Nutrients
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question 20 data was collected for a sample of organic snacks. the amou…
51
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add a methyl substituent at carbon #3, an ethyl substituent at carbon #…
\( \text{CH}_3\text{CH}_2\text{CH}(\text{CH}_3)\text{CH}_2\text{CH}(\text{C}_2\text{H}_5)\text{CH}(\text{C}_3\text{H}_7)\text{CH}_2\text{CH}_2\text{CH}_3 \)
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data was collected for a sample of organic snacks. the amount of sugar …
44
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add an ethyl substituent at carbon #3 to this organic molecule. be sure…
The skeletal structure with an ethyl substituent at carbon #3 is: ``` ── / ─C─C─C─C | ─ \ ── ``` (or in a more standard drawing: CH₃ / C₁─C₃─C₄ | C₂ \ CH₂ But in pure skeletal (li…
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calculate the percent by mass of $\\ce{k_{2}co_{3}}$ in a saturated sol…
\(\boxed{57\%}\) (or depending on graph reading precision, could be ~56% - 57%, but with two sig figs, 57% is appropriate)
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5. calculate the osmotic concentration (osmolarity) of a 0.5 m nacl sol…
1.0 Osm/L
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millions of years ago, tiny marine organisms died and sank to the ocean…
- Petroleum reservoirs are often found in sedimentary rocks that formed in ancient marine environments. - Petroleum is chemically similar to the remains of marine organisms like b…
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water drops or ice crystals. the tiny drops of water or ice crystals co…
Clouds form when water vapor condenses onto particles like dust to create droplets; moist, warm air rises because it is less dense than surrounding cooler air and continues to ris…
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questions do a, c, e 2. predict the electron configuration of each of t…
\( 1s^2 2s^2 2p^2 \) ### Question 2(c): Predict electron configuration of \( _7\text{N}^{3+} \)
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preparation before beginning the time study, complete the five question…
To solve for the number of protons, neutrons, and electrons in an atom, we use the following concepts: - **Protons**: Equal to the atomic number (\(Z\)) of the element. - **Electr…
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6. what is the most important type of physical weathering in high mount…
6. C. Frost wedging 8. D. Physical weathering
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5. frost wedging breaks rock apart because a.rocks contract when they b…
5. D. Water expands when it freezes 7. B. Breakdown 9. B. Its total surface area increases
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base your answers to questions 14 through 16 on the diagram of bowen’s …
1. El feldespato plagioclasio de la roca basáltica es rico en calcio y se forma a temperaturas altas, mientras que el de la roca granítica es rico en sodio y se forma a temperatur…
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part a choose the sketch of the mass spectrum of rhenium where the tota…
The second graph (with \(^{187}\text{Re}\) at 100% intensity and \(^{185}\text{Re}\) at ~60% intensity, labeled with the second radio button)
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3. sep analyze data calculate the ratio of the moles of product produce…
To solve this, we need the moles of product and moles of each reactant (let's assume a chemical reaction, say \( aA + bB ightarrow cC \), where \( A, B \) are reactants, \( C \) i…
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question 1 (2 points) read and complete each procedure step for lab 3, …
To solve this, you would first refer to your eScience Lab Manual, locate Table 1: Powder Mass, and then find the value listed for the total powder mass (in grams) from that table.…
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analyzing data proportional relationships in chemical reactions a chemi…
The table with changes is as above. For each trial: - Trial 1: \( N_2 \): 0.010, \( H_2 \): 0.030, \( NH_3 \): 0.020 - Trial 2: \( N_2 \): 0.070, \( H_2 \): 0.210, \( NH_3 \): 0.1…
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complete the sentences to explain the difference match the items in the…
1. Fluorine has $\boldsymbol{\text{one}}$ major isotope(s) corresponding to $\boldsymbol{\text{isotope F - 19}}$. Thus, the atomic mass of fluorine is equal to $\boldsymbol{\text{…
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two 20.0 g ice cubes at (-13.0) °c are placed into 245 g of water at 25…
$9.39^\circ\text{C}$
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lithium has only two naturally occurring isotopes. the mass of lithium …
7.5, 92.5
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do you expect the atomic mass of the element to be closer to that of is…
The average atomic mass will be closer to the mass of \(\boldsymbol{\text{isotope A}}\) because there is about \(\boldsymbol{\text{three}}\) times as much of \(\boldsymbol{\text{i…
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question 32 of 34 consider a hexagonal close - packed unit cell, as sho…
fraction inside the cell: $\frac{1}{2}$ number of atoms inside the cell: 6
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what kind of information can be determined from a mass spectrum? match …
1. The result of the mass spectrometer is the separation of the atoms in the sample according to their $\boldsymbol{\text{mass}}$, producing a $\boldsymbol{\text{mass spectrum}}$.…