化學
化學反應、化學計量、分子結構與元素性質。
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and ___ are the two subatomic particles found in an element’s a electro…
B. neutrons, protons
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______ structure controls the physical properties of elements. a nucleu…
B. Electron
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how many valence electrons do noble gases have? a seven b eight c six
B. eight
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nutrition crossword 9 use the clues provided to complete the crossword …
To solve this nutrition - related crossword puzzle, we analyze each clue: ### Across Clues - **4. Certain foods affect the chemistry of this**: The answer is "BRAIN" (length 5). F…
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7. what coefficients would correctly balance this equation? \\( \\ce{na…
d. 1, 3, 3, 1
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7. what coefficients would correctly balance this equation? na₃po₄ + ko…
7. a. 1, 3, 3, 3 8. d. 1, 1, 1, 2
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balancing equations name 1. a chemical reaction is a process in which a…
1. b. the law of conservation of mass applies 2. b. atoms are rearranged 3. b. adding coefficients 4. d. outermost electrons 5. c. zinc and copper (II) sulfate
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2) if 3.00 moles of h₂o are produced, how many moles of oxygen must be …
2) 1.50 moles of $\text{O}_2$ 3) 2.5 moles of $\text{H}_2$
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drag the correct answer to the box. which counterclaim would help balan…
Herbicides quickly kill weed roots while preserving grass, making them efficient and easy gardening tools.
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regina is writing an argument against adding fluoride to the city’s dri…
D. The Food and Drug Administration stated in 2000 that fluoride is a drug subject to regulation when it is "used in the diagnosis, cure, mitigation, treatment, or prevention of d…
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bell work january 29, 2026 what are the oxidation number of the followi…
1. Iodine: 0 (if elemental); in compounds, depends on the compound, but likely 0 here. 2. Magnesium: 0 (if elemental); in compounds, +2 (group 2 metal). 3. Carbon: 0 (if elemental…
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practice: isotope calculations #1 part 1 use the notation below to answ…
isotopes 2.
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calculate the average atomic mass for oxygen given the following; isoto…
s (matching each blank): 1. E (0.997572) 2. B (15.9994791) 3. D (0.000381) 4. H (0.0064767) 5. C (0.0020514) 6. G (0.03692348) 7. A (15.9995) 8. E (0.997572)
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calculate the average atomic mass for an unidentified element given the…
s (for each blank): 1. \( 0.78994 \) (Option F) 2. \( 18.946744 \) (Option G) 3. \( 0.10001 \) (Option E) 4. \( 2.498834 \) (Option I) 5. \( 0.11013 \) (Option D) 6. \( 2.861463 \…
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calculate the average atomic mass for oxygen given the following; isoto…
For blank 1: 0.997572 (Option E) For blank 2: 15.9994791 (Option B) For blank 3: 0.000381 (Option D) For blank 4: 0.0064767 (Option H) For blank 5: 0.0020514 (Option C) For blank …
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read the passage from a letter that president jimmy carter wrote to con…
Protecting the environment is essential for maintaining Americans' quality of life.
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question 6 (1 point) convert 454 in³ into cm³ and into ml. (2.54 cm = 1…
\(7.44\times 10^{3}\) (or \(7440\))
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question 4 (2 points) convert 454 in³ into cm³ and into ml. (2.54 cm = …
The correct conversion factor is \(\frac{16.387\ \text{cm}^3}{1\ \text{in}^3}\), so the second option's blank is filled with \(\frac{16.387\ \text{cm}^3}{1\ \text{in}^3}\) and the…
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question 3 (2 points) convert 454 in³ into cm³ and into ml. (2.54 cm = …
The correct conversion factor is \( (2.54\ \text{cm})^3=(1\ \text{in})^3 \) leading to \( 16.387\ \text{cm}^3 = 1\ \text{in}^3 \). \( 454\ \text{in}^3 = 454\times16.387\ \text{cm}…
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a chemist has 500 ml of a 30% acid solution. she adds x milliliters of …
The horizontal asymptote $y = 10$ means that the final concentration will always be greater than 10%.
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diluted to have 30% acidity. the graph models the percent of acidity in…
30 liters *Correction note: Rechecking the graph, when $y=0.3$, the $x$ value is 30 liters. The correct mixture equation assumes starting with 30L of 50% acid: $$0.5(30) + 0.2x = …
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the mass of a hydrogen atom is about 1.67e-24 grams. the mass of a plut…
A. $2.43 \times 10^{2}$
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in this lab, you will conduct a series of reactions and then classify e…
products
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how do you know there was a chemical reaction? check all indicators bel…
A. A solid precipitate formed. B. The color changed. C. A gas was produced. D. The reaction absorbed or released heat.
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fill in the blanks in the sentence below. in the reaction at blood fall…
For the first blank (reactants): iron, oxygen, and water For the second blank (product): iron oxide (rust)
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question 18 which of the following is chemically inert (unreactive)? ○ …
C. neon (atomic number 10)
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question 16 what type of chemical bond can form between an atom with 11…
B. ionic
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considering the activity series given for nonmetals, what is the result…
no reaction
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which products would form if chlorine gas was bubbled through a solutio…
C. NaCl and Br₂
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question 12 4 points what does ch4 mean? ○ this is an inorganic molecul…
B. There is one carbon and four hydrogen atoms.
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in which type of chemical reaction do two or more substances combine to…
A. synthesis
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which type of chemical reaction occurs in ca + cl2 → cacl2? synthesis c…
A. synthesis
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sodium chloride reacts with copper sulfate to produce sodium sulfate an…
double replacement reaction.
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which is a characteristic of a decomposition reaction? substance p repl…
Substance XYZ breaks down into X, Y, and Z.
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reaction occurs when one compound reacts and is broken down into differ…
decomposition
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propane burns in air to produce carbon dioxide and water. what is this …
B. combustion
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smoker’s toothpaste actually has corundum in it! corundum has a hardnes…
Corundum is harder than the apatite that makes up your teeth ### Second Part (Short - Answer)
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a double replacement reaction can be best described as a reaction in wh…
ions are exchanged between two compounds.
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which type of chemical reaction occurs in 2kclo3 → 2kcl + 3o2? ○ synthe…
B. decomposition
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question 9 4 points an acid with a ph of 6 has ______ hydrogen ions tha…
D. 10 - fold more
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choose the correct products for the double replacement reaction below. …
s: - Correct products: \( \text{KNO}_3 + \text{AgCl} \) - Precipitate product: \( \text{AgCl} \)
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the main mineral making up your teeth is the mineral apatite. according…
Silica (quartz) is harder
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choose the correct products for the double replacement reaction below. …
B. \( \text{KNO}_3 + \text{AgCl} \) (assuming the option with \( \text{KNO}_3 + \text{AgCl} \) is labeled as B, adjust the label as per the original question's option numbering if…
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question 7 the chemical symbol o=o means ______. this is an ionic bond …
D. the atoms are double bonded (assuming the last option is labeled D; if the original options had labels like A - D, with the last option being the correct one, the answer is the…
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choose the correct products for the double replacement reaction below. …
- Correct products: \( \text{PbSO}_4 + \text{MgCl}_2 \) - Precipitate - forming product: \( \text{PbSO}_4 \)
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choose the correct products for the double replacement reaction below. …
\( \text{PbSO}_4 + \text{MgCl}_2 \) (corresponding to the option "PbSO₄ + MgCl₂")
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complete the following equations (note that the equations are not balan…
no reaction (the option: no reaction)
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complete the following equations (note that the equations are not balan…
A. \( \text{AlCl}_3 + \text{Ag} \)
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use the activity series below to predict whether the following reaction…
s: - For the reaction $\boldsymbol{Cl_2 + 2RbI ightarrow 2RbCl + I_2}$: The reaction will take place. - For the reaction $\boldsymbol{I_2 + NiBr_2 ightarrow NiI_2 + Br_2}$: The re…
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use the activity series below to predict whether the following reaction…
s: - For $\ce{Ca + ZnBr_2 ightarrow CaBr_2 + Zn}$: The reaction will take place. - For $\ce{Cu + 2KNO_3 ightarrow Cu(NO_3)_2 + 2K}$: The reaction will not take place.
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use the activity series below to predict whether the following reaction…
s: - For \( \text{Ag} + \text{NaNO}_3 ightarrow \text{AgNO}_3 + \text{Na} \): The reaction does not take place. - For \( \text{Mn} + \text{CaO} ightarrow \text{Ca} + \text{MnO} \)…
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predict the missing component of each reaction.\ $2\\ce{na} + \\ce{cl_{…
s: For $2\text{Na} + \text{Cl}_2 ightarrow ?$: $\boldsymbol{2\text{NaCl}}$ For $2\text{MgO} ightarrow ?$: $\boldsymbol{2\text{Mg} + \text{O}_2}$
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predict the missing component of each reaction. ? + 2nabr → 2nacl + br₂…
First reaction: $\boldsymbol{\text{Cl}_2}$ (from the options: $\boldsymbol{\text{Cl}_2}$) Second reaction: $\boldsymbol{\text{CO}_2 + 2\text{H}_2\text{O}}$ (from the options: $\bo…
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classify each of the following chemical reactions. $\\ce{s + o_{2} \ ig…
for $\boldsymbol{\ce{S + O_{2} ightarrow SO_{2}}}$: synthesis and combustion ### For $\boldsymbol{\ce{2Na_{2}O ightarrow 4Na + O_{2}}}$ (decomposition: AB → A + B, here $\ce{Na_{2…
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use the activity series below to predict the products of each of the fo…
C. $Ca_3(PO_4)_2 + Zn$
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separation of mixture* objectives: 1) learn different separation techni…
The purpose of filtration is to separate sand (solid clumps with larger particle size) from the liquid portion (water and dissolved salt, with smaller particle size/molecules) of …
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use the activity series below to predict the products of each of the fo…
no reaction
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use the activity series below to predict the products of each of the fo…
s: - For \( \ce{Na2CO3 + K ightarrow} \): \( \ce{K2CO3 + Na} \) - For \( \ce{ZnCl2 + Cu ightarrow} \): no reaction
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use the activity series below to predict the products of each of the fo…
B. \(K_2CO_3 + Na\) (assuming the second option is labeled as B, if the original options had labels like A, B, C with A being "no reaction", B being \(K_2CO_3 + Na\) and C being \…
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you may have noticed an (s) next to one of the products in some double …
iron (III) hydroxide
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eplacement reactions given. check to see that the equations are bacl₂ +…
\(BaSO_{4}(s)+MgCl_{2}\) (the last option: \(BaSO_{4}(s)+MgCl_{2}\))
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predict the products of the double replacement reactions given. check t…
B. $\ce{NaNO_3 + AgCl (s)}$
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single replacement reactions given. check to see that the equations are…
\(ZnCl_{2}+H_{2}\) (corresponding to the option " \(ZnCl_{2}+H_{2}\)")
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predict the products for the single replacement reactions given. check …
A. $CaCl_2 + Mg$
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select the description of each substance given by each chemical formula…
One molecule of $\text{O}_3$ is made of three atoms of oxygen The compound $\text{Al}_2\text{O}_3$ is made of two atoms of aluminum and three atoms of oxygen The compound $\text{K…
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what type of reaction is shown below? check all that apply. 2na + cl₂ →…
A. synthesis
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fluorine (f) and bromine (br) are in the same group on the periodic tab…
D. Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable
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what type of reaction is shown below? check all that apply. 2h₂o₂ → 2h₂…
B. decomposition
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what type of reaction is shown below? check all that apply. 2mg+o₂→2mgo…
A. synthesis, C. combustion
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what type of reaction is shown below? check all that apply. $\\ce{c_{10…
combustion (the checkbox next to "combustion" should be selected)
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complete the passage to describe how electrons are represented in elect…
The maximum number of dots an electron dot diagram can have is eight The maximum number of dots drawn on a side of a chemical symbol in an electron dot diagram is two
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which model correctly represents the electron dot diagram of antimony?
D. $\dot{\underset{\cdot \cdot}{Sb}} \dot{}$ (the fourth option with Sb and 5 valence electrons)
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does the model correctly represent the electron dot diagram of magnesiu…
B. Yes, because the chemical symbol of magnesium is Mg D. Yes, because magnesium has two valence electrons
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creating electron dot diagrams order the steps to take when drawing ele…
1. Use the periodic table to find the chemical symbol of the atom and the number of electrons in the valence shell. 2. Write the chemical symbol of the atom. 3. Draw dots around t…
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reating electron dot diagrams order the steps to take when drawing elec…
1. Use the periodic table to find the chemical symbol of the atom and the number of electrons in the valence shell. 2. Write the chemical symbol of the atom. 3. Draw dots around t…
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describing electron dot diagrams what information is shown in an atom’s…
the number of valence electrons an atom has
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calcium chloride is used to make pickles. the calcium atom transfers el…
Calcium chloride contains **ionic** bonds Pennies contain **metallic** bonds Hydrochloric acid contains **covalent** bonds
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complete the sentence. atoms form chemical bonds to satisfy the rule an…
First blank: octet Second blank: stable
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identifying electron dot diagrams which model represents the electron d…
The first model: .$\ddot{\text{Si}}$$\boldsymbol{\cdot}$ (with one dot on the left, two on top, one on the right, one on the bottom, totaling 4 valence electrons)
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Question was provided via image upload.
The first dot should be placed **directly above the "Cl" symbol** (the top position relative to the chemical symbol).
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ng electron dot diagrams construct the electron dot diagrams for chlori…
Step 1 answer: $\text{Cl}$ Step 2 answer: 7
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creating electron dot diagrams construct the electron dot diagram for c…
Cl
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which of the following signs of a chemical reaction are observed in the…
- temperature change (the reaction is exothermic, so temperature increases) - gas produced (hydrogen gas is released: \(2K + 2H_2O = 2KOH+H_2\uparrow\)) - color change (the soluti…
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activity c (continued from previous page) 4. compare: the accepted valu…
\( V = 11.2\ \text{L} \) (or \( 11.20\ \text{L} \) depending on rounding) ### 7B Solution:
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using the periodic table to find the number of valence electrons of an …
4
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which word equation shows hydrogen reacting with oxygen to form water? …
B. hydrogen + oxygen $ ightarrow$ water (Note: Here the option identifier is assumed as B as per the standard multiple - choice format where the second option is correct. If the o…
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which statement best describes the formula equation $\\ce{cl_2(g) + 2kb…
D. Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
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which formula equation represents the burning of sulfur to produce sulf…
A. \( \text{S(s)} + \text{O}_2\text{(g)} \xrightarrow{\Delta} \text{SO}_2\text{(g)} \)
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describing types of chemical bonds match each bond with the rearrangeme…
- Ionic bond: transferring of electrons - Covalent bond: sharing of electrons - Metallic bond: sharing of many electrons
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in a chemical equation, which symbol should be used to indicate that a …
D. (aq)
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what is the formula equation for the reaction between sulfuric acid and…
C. $\ce{H2SO4(aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l)}$ (Note: Using option identifier as per the original, assuming the third option is C here. If the original options were labele…
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the compound $\\ce{co_{2}}$ is made of two atoms of cobalt. one atom of…
D. one atom of carbon and two atoms of oxygen.
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fluorine gas is placed in contact with calcium metal at high temperatur…
D. $\ce{F2(g) + Ca(s) \stackrel{\Delta}{ ightarrow} CaF2(s)}$ (Note: In the original options, the fourth option is the correct one with the identifiers as per the problem's option…
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your calculation is incorrect liquid level measurement \t\t\tml\t\tl wa…
0.05
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module 0: intro. to chemistry and measurement 8. how many significant d…
8. 5 9. 6 10. a. $7.5\ \text{cm}^2$ b. $12.46\ \text{m}$ c. $6.3 \times 10^{-9}\ \text{m}^2$ 11. a. $10^3$ b. $10^2$ c. $10^1$ d. 1 e. $10^{-1}$ f. $10^{-2}$ g. $10^{-3}$ 12. $6.0…
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according to the law of conservation of, the number of atoms in the pro…
mass
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down 1 a game you play with xs and os 2 a type of state you might see i…
To solve this crossword puzzle, we analyze each clue: ### Across Clues: 1. **A game you play with X’s and O’s** → *TIC-TAC-TOE* (matches the grid’s length, with “TIC” as the first…
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satisfying the octet rule how many additional electrons does this atom …
two
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which equation has both a liquid and a gas as products? 2hgo(s) → 2hg(l…
A. \(2\text{HgO}(s) ightarrow 2\text{Hg}(l) + \text{O}_2(g)\)
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module 0: intro. to chemistry and measurement module 0 study guide (to …
1. $\boldsymbol{3.86 \times 10^5}$ km 2. $\boldsymbol{9.30 \times 10^{-3}}$ m 3. Accuracy: Poor; Precision: Poor 4. Accuracy: Poor; Precision: Good 5. $\boldsymbol{\approx 2.34\%}…