化學
化學反應、化學計量、分子結構與元素性質。
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activity in this activity, you will use data obtained in a laboratory t…
- Moles of carbon: $\boldsymbol{19.32}$ - Moles of hydrogen: $\boldsymbol{57.54}$ - Moles of oxygen: $\boldsymbol{9.69}$
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calculate the molecular formula of the compound. use the periodic table…
\( \text{S}_2\text{O}_2 \) (Wait, but actually, maybe the empirical formula is \( \text{SO} \), but the molecular formula is \( \text{S}_2\text{O}_2 \), or is there a mistake? Wai…
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select the correct answer from each drop - down menu. a sample of a com…
The mass percent of chlorine is 65.6%, so the correct option from the dropdown (for chlorine's percent) is 65.6%. The empirical formula is $\text{FeCl}_3$, so the subscripts would…
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select the correct answer from each drop - down menu. a sample of a com…
For the percent composition of iron: 34.4% (the option with 34.4%). For the empirical formula, the subscript of Fe is 1 and Cl is 3 (but based on the drop - down, if the first dro…
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select the correct answer from each drop - down menu. a sample of a com…
The empirical formula is \(FeCl_3\) (so the subscripts are 1 for Fe and 3 for Cl).
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select the correct answer. what is the empirical formula for ribose (c₅…
\(CH_2O\) (the option with formula \(CH_2O\))
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you have a solution with 2.52 moles of isopropanol (c₃h₈o). the solutio…
29%
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what is the percent composition of calcium in calcium chloride (cacl₂)?…
36
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which statement describes indoor air pollution? smog is a common source…
Ultrafine particles are classified as indoor air pollutants.
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which is the best strategy for addressing polluted air? ○ reduce the co…
B. Study the effects of mold exposure on people who suffer from asthma.
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3 this question has two parts. find answer part a. then answer part b. …
C. checked to see if something works ### Question 3 (Part B)
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howard has a chemical burn from accidentally spilling a strong basic cl…
A. Acute
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unit 7 mole concept exam review 1. how many molecules are in 0.45 mole …
1. $2.71\times10^{23}$ molecules 2. $\approx0.27$ moles 3. $342\ \text{g/mol}$ 4. $\approx1.86\ \text{g}$ 5. $\approx1.68\times10^{24}$ atoms 6. d) Grams of oxygen in 1 mole 7. c.…
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what is the rhyme scheme of the first stanza?\ poetic structure does ma…
aabb
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use the drop - down menus to answer the questio about john masefields p…
three
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what did you notice about this poems structure as you listened? check a…
B. It does not have a specific rhyme scheme, D. It has a free form, E. It does not have a set meter (Note: The actual correct options depend on the specific poem, but these are th…
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chemiscopes might help scientists in the future by... (check all that a…
- showing scientists how chemical reactions take place
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which is a nonpoint source of pollution? tourists throw trash into the …
C. Rain contains chemicals that seep into the ground.
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how would fdrs court - packing scheme have changed the supreme court? i…
It would have expanded the Court by allowing the president to appoint new justices when existing justices turned 70.
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what is one way people positively affect water resources? polluting fro…
D. limiting use of acid and other pollutants
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(20) sep interpret data use the phase diagram for carbon dioxide (co₂) …
1. At STP, CO₂ is in the **gas** phase. 2. The normal sublimation temperature of carbon dioxide is $\boldsymbol{-78.5^\circ C}$ (or 194.7 K).
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oil is a fossil fuel used to run cars, heat up homes, and produce elect…
- air - water - organisms in water
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instructions choose an answer and hit next. you will receive your score…
Figure out the exact machine that made the document
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alex could not figure out a problem on her chemistry homework. she deci…
A. insight learning.
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when 100. g of gaseous water decomposes 1337 kj of heat are used by the…
$1423.6\ \text{kJ}$ (rounded to 1 decimal place, or $1424\ \text{kJ}$ rounded to whole number) Filled proportion for the given template: $$\frac{1337}{16} = \frac{x}{17}$$ *(16 co…
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protons, neutrons, and electrons worksheet | atomic symbol | atomic num…
| Atomic symbol | Atomic number | Protons | Neutrons | Electrons | Atomic mass | Charge | |---------------|---------------|---------|----------|-----------|-------------|--------|…
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what mass of propane would be required to supply -6.22e+4 kj of heat? c…
$5.48\times10^4$ g
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30. g of c₃h₈ (propane) undergoes combustion and produces 34 kj of heat…
14 kJ of heat is produced (or -14 kJ if sign denotes heat release)
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how many moles would be present in 300 liters of dinitrogen monoxide at…
c. 13.4 moles
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what quantity is needed to convert between the moles of a given gaseous…
b. the molar volume
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convert 4.92 l of hydrogen at stp to moles. a 0.202 mol $h_2$ b 4.55 mo…
c. 0.220 mol $H_2$
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what is the mass of 61.9 l of oxygen gas collected at stp?a 88.4 g o₂b …
a. \(88.4\ g\ O_2\)
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calculate what will be the volume of 10.0 grams of gaseous ammonia (nh₃…
a. 13.2 L
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calculate what will be the volume of 17.0 grams of ammonia (nh₃) at stp?
C. 13.1 L
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what will be the volume occupied by 100 grams of oxygen gas at stp? a 3…
b. 70 L
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a 5.00 l flask contains 7.94 g of a gas at stp. what is the molar mass …
d. 35.6 g/mol
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choosing appropriate hypotheses this lab question is: how can you disti…
- [x] If a substance changes state of matter (e.g., liquid to gas), then this is a physical change because the original properties of the substance have not changed. - [x] If a su…
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15. which shows a correct comparison? a 5 milliliters > 50 liters b 2 l…
D. 3,200 milliliters > 3 liters
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in 4-6, tell what metric unit y 4. medicine in a pill
The metric unit for the medicine in a pill is milligram (mg) (or microgram (μg) for very small quantities, but milligram is more common for typical pills).
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density describes how much mass is contained in a certain volume. knowi…
Gasses are less dense than solids.
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mercurys natural state is where the atoms are close to each other but a…
B. liquid
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michael has a substance that he puts in container 1. the substance has …
D. gas
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density involves the amount of a material in a certain volume. when a m…
C. The liquid state is more dense than the solid state.
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chemical bonding why do bonds form? atoms bond because they become more…
s (filling the blanks): #### Why do bonds form? - stable - completed - outer - losing - gaining - electrons - octet - outer #### Ionic Bonding - metal - electrons - non - metal - …
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when organic matter becomes trapped underground, it may be transformed …
B. fossil fuels
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please answer the following questions in small groups. in 25 min, we wi…
1. $28\ \text{g/mol}$ 2. $6.022 \times 10^{23}\ \text{atoms}$ 3. $0.0357\ \text{mol}$ (rounded to 4 significant figures) 4. $2.15 \times 10^{22}\ \text{atoms}$ (rounded to 3 signi…
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1. what is the molar mass (mw) of your element? (include units) 2. how …
1. $12.01\ \text{g/mol}$ 2. $6.022 \times 10^{23}$ atoms 3. $0.08326\ \text{mol}$ 4. $5.014 \times 10^{22}$ atoms
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carbon tends to form ______ bonds. choose one option a stable b precari…
A. stable
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lohse, chem 181 exam 1 review: subatomic structure names: please answer…
### Completed Table: | Element | Boron (B) | Nickel (Ni) | Krypton (Kr) | Fluorine (F) | |-----------------------|-----------|-------------|--------------|--------------| | Atomic…
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1. $c_2h_4$ 2. $co_2$ single, double, and/or triple bonds: 1. $n_2$ 2. …
To determine the types of bonds (single, double, triple) in each molecule, we analyze their Lewis structures and bonding: ### 1. $\boldsymbol{C_2H_4}$ (Ethene) - **Step 1**: Carbo…
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using your activity series, determine if the reactions below will occur…
a. No Reaction b. $\boldsymbol{\text{MgCl}_2 + \text{Ba} ightarrow \text{Mg} + \text{BaCl}_2}$ c. $\boldsymbol{\text{Zn} + 2\text{HCl} ightarrow \text{H}_2 + \text{ZnCl}_2}$ d. $\…
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changes in matter quiz complete 1 2 3 4 5 6 7 8 9 10 which term refers …
extensive
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changes in matter quiz complete 1 2 3 4 5 6 7 8 9 which of these is an …
volume
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a student performs the following experiment. step 1: she pours a colorl…
a. a chemical change in step 1 and a physical change in step 2
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changes in matter quiz complete 7 which is an intensive property of a s…
density
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a geochemist examines a piece of metal that he found in the soil. he pe…
He is identifying the metal using physical properties only.
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to observe a property of a substance, the substance must interact with …
chemical
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changes in matter quiz complete 1 2 3 4 which of these is a chemical pr…
reactivity
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changes in matter quiz complete which of these is an example of investi…
determining if a rock is magnetic
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changes in matter quiz complete which statement describes a physical pr…
It can be reshaped by a force.
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changes in matter quiz complete 1 which is an example of a chemical cha…
bread baking in an oven
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describing physical and chemical changes an industrial chemist is study…
Physical changes to identify the metal: 1. Shape/Size Alteration: Cut or bend the metal to test malleability, a physical property unique to some metals. 2. Phase Change: Melt the …
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measurements show that unknown compound x has the following composition…
$\boxed{CH_4}$
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day 1: homework 1. circle any reactions that will not occur. ba + nullo…
The reactions that will NOT occur are: 1. $\text{Ba} + \text{NaNO}_3$ 2. $\text{KCl} + \text{Ni}$ 3. $\text{HBr} + \text{Au}$
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measurements show that unknown compound x has the following composition…
$\text{Cr}_2\text{O}_3$
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5 a scientist used 786 milliliters of a liquid for an experiment. how m…
C 0.786 L
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write the chemical symbols for three different atomic anions that all h…
$C^{4-}$, $C^{3-}$, $C^{2-}$
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15 why must accidents be reported immediately, even if no injury is vis…
Accidents must be reported immediately (even without visible injury) because they may cause hidden harm (e.g., chemical exposure effects, equipment damage), allow timely risk asse…
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a certain chemical reaction releases 34.5 kj/g of heat for each gram of…
\(\frac{\frac{1780.}{1000}\space kJ}{34.5\space kJ/g}\)
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6. look at elements 3 to 10. a) draw bohr diagrams for these elements b…
### Part (a) Drawing Bohr Diagrams Elements 3 (Lithium, \( \text{Li} \)) to 10 (Neon, \( \text{Ne} \)) have the following Bohr diagrams: - **Lithium (Li, Atomic Number = 3):** - N…
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identifying physical and chemical changes the list below includes some …
- burns readily in air - does not react with water
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8. an artist is using wooden cubes to build a statue. yesterday, she pl…
b. Before the cubes touch, the bottom cube is hotter than the top cube. Once the cubes are touching, the bottom cube will transfer kinetic energy to the molecules in the cooler to…
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station 2: lab safety scenarios task: read each scenario and write the …
To answer the questions related to lab safety scenarios (questions 5 and 6), we analyze each situation based on standard lab safety protocols: ### Question 5: A chemical spills on…
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5. aki is playing cards and is about to put one card on top of another.…
C. Before the cards touch, the top card is hotter than the bottom card. Once the cards are touching, the top card will transfer kinetic energy to the molecules in the cooler botto…
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20 multiple choice 1 point what is one of the possible hazards related …
20. Slippery surfaces 21. Working with clarifiers
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18 multiple choice 1 point process technicians are responsible for perf…
18. Sample water and add chemicals as needed. 19. Cleaning screens
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which of the following water systems requires process technicians to mo…
1. Firewater systems 2. B. Raw water supply systems 3. A. Clean and inspect screens.
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geologists classify 1 rocks in three groups, according to the major ear…
D. a coarse - grained rock forms.
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identifying physical and chemical changes the list below includes some …
☑️ gas at room temperature ☑️ strong, unpleasant odor ☑️ dissolves easily in water
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element valence\tmetal nonmetal\tneutral atom (drawing)\tgain lose\tion…
To solve this problem, we analyze each element based on its properties (metal/nonmetal, valence, electron gain/loss, ion type, and Lewis dot structures for neutral atoms and ions)…
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in this text, rachel m. barker discusses different types of rocks. geol…
D. It establishes the importance of knowing the main rock types.
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in this text, rachel m. barker discusses different types of rocks. geol…
B. There are three main types of rocks that are grouped by how they form.
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complete the sentences to explain why scientists were concerned about t…
1. decrease 2. UVB
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read the text. during world war i, british and american warships were a…
problem - solution
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what do these two changes have in common? water vapor condensing on a b…
- Both are caused by cooling. - Both are changes of state.
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what do these two changes have in common? salt and vinegar removing tar…
Both conserve mass.
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select all the examples of a chemical change. ice melting nail rusting …
B. nail rusting, C. bread baking, D. wood burning, E. milk spoiling
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read the text. when a person ingests caffeine, whether in the form of a…
sequential
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part 4: complete the following questions 1) a gas behaves like an ideal…
Let's solve these questions one by one: ### Question 1 - An ideal gas behaves ideally at **low** pressure and **high** temperature (because at low pressure, the volume of gas mole…
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which of the following are negative impacts on land resources caused by…
- erosion increase due to road construction - chemicals used in mining entering the soil - desertification caused by deforestation
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13. communicate and justify during a chemistry experiment, julian recor…
Independent variable: Time (in minutes) because it is the variable that is controlled or changed in the experiment. Dependent variable: Temperature (in \(^\circ\text{C}\)) because…
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email to xjimenez@mustangsla - select the element that is not a halogen…
a) Rg
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• rule 1: all nonzero digits are significant. • rule 2: zeros between t…
A) 3 sf B) 3 sf C) 4 sf D) 3 sf E) 6 sf F) 5 sf G) 7 sf H) 4 sf I) 6 sf J) 5 sf --- ### Part 2: Exact vs Measured Numbers
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5. write electron configurations for the following. a. calcium b. zirco…
\(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2\) or \([Ar]4s^2\) (where \([Ar]\) is the electron configuration of argon, \(1s^2 2s^2 2p^6 3s^2 3p^6\)) ### Part b: Zirconium (Zr)
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1. outline the trends of the periodic table for ionization energy, atom…
(a) F (Fluorine) (b) Claim: Mg (Magnesium) is the smallest metal radius. Evidence: Mg has 3 energy levels; Cs has 6. Reasoning: Fewer energy levels mean stronger nuclear attractio…
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what determines periodicity in the modern periodic table? the number of…
C. The electron configuration
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who is credited with the discovery of phosphorus, the fifteenth element…
Hennig Brandt
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what did john dalton propose in 1803? he theory of relativity the exist…
D. Atoms were at work in chemical reactions
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lesson 3 electron configurations practice date period multiple choice 1…
d. 7 ### Question 2
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what was the first man - made element? einsteinium technetium flerovium…
B. Technetium