化学
化学反应、化学计量、分子结构与元素性质。
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2) 6 c carbon 12.01 protons: neutrons: electrons: valence electrons: 3)…
Protons: 2 Neutrons: 2 Electrons: 2 Valence Electrons: 2
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missed this? watch kcv: reaction stoichiometry, iwe: mass-to-mass conve…
To solve for the mass of \( \ce{CO2} \) produced, follow these steps (example with assumed moles, adjust for actual values): ### Step 1: Balanced Reaction \( \ce{2HCl(aq) + Na2CO3…
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missed this? watch kcv: reaction stoichiometry, iwe: mass-to-mass conve…
\( \approx 111 \, \text{g} \)
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mole test review: due problems: for the following problems, show all wo…
\( 2.17 \times 10^{24} \) atoms of carbon ### Problem 5: Moles of hydrogen in 362.8 g of \( \text{H}_2 \)
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question 12 (1 point) retake question if 50 ml of h₂so₄ yields 0.300 g …
\( \approx 0.0257 \) (or more precisely, using exact calculation: \( \frac{0.300}{233.40\times0.050} \approx 0.0257 \))
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impossibilities, and performed nothing. the modern masters... penetrate…
C. The pursuit of knowledge
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when 0.25 mg\\(_{(s)}\\) is added to 250ml of 3.00 mol/l hcl\\(_{(aq)}\…
0.0257 (or approximately 0.026)
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what is the concentration of a solution which has 100.0g of lead(ii) ni…
First sub - question: \(\approx0.604\space mol/L\) (or more accurately, \(\frac{100}{331.2\times0.5}\approx0.604\space mol/L\)) Second sub - question: \(0.150\space mol/L\)
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3. figure 9 represents acids and related entities at the molecular leve…
(a) Diagram (iii) – HCl is a strong acid, fully dissociates into \( \text{H}^+ \) and \( \text{Cl}^- \) ions (no intact molecules). (b) Diagram (ii) – Ethanoic acid is weak, parti…
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calculate the heat of reaction δh for the following reaction: 2hcl(g) +…
$\boxed{-351}$
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Question was provided via image upload.
\(\boldsymbol{-1050}\) (rounded to nearest kJ/mol, depending on bond energy precision, but standard calculation gives \(-1050\) kJ/mol)
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calculate the heat of reaction δh for the following reaction: 2 hcl(g) …
$\boxed{80}$ (kJ/mol)
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calculate the heat of reaction δh for the following reaction: 2 hcl(g) …
\(\boxed{80}\) (in \(\frac{\text{kJ}}{\text{mol}}\))
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a chemist measures the enthalpy change δh during the following reaction…
For the first reaction: \( 276\ \text{kJ} \) For the second reaction: \( -35\ \text{kJ} \) For the third reaction: \( 69\ \text{kJ} \)
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a chemist measures the enthalpy change δh during the following reaction…
For the first reaction \( \ce{3CH4(g) + 3CO2(g) -> C6H12O6(s)} \), \( \Delta H = 132\space kJ \) For the second reaction \( \ce{\frac{1}{2}CH4(g) + \frac{1}{2}CO2(g) -> \frac{1}{6…
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a chemist measures the enthalpy change δh during the following reaction…
First reaction \( \Delta H \): \(-44\) kJ Second reaction \( \Delta H \): \(132\) kJ Third reaction \( \Delta H \): \(264\) kJ (If the table requires filling each box: first box -…
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5. an empty can weighs 30 grams. the weight of the same can filled with…
\( w + 30 = 47.3 \) (the last option, assuming the options are ordered as shown: the fourth option with \( w + 30 = 47.3 \))
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using the appropriate bond energies, calculate the heat of reaction δh …
\(-482\ \text{kJ/mol}\)
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match the perspective in column 1 to the corresponding question in colu…
- Positive psychology: How can I lead a more meaningful life? - Developmental psychology: Why do babies like to play hide - and - go - seek? - Biopsychology: What does depression …
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despite being raised in a time and place in which black students were p…
B. Was
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name___________________________ period __________ date _______________ …
Let's summarize each row (filling blanks): 1) (Given: \(Z=17\), \(A=36\)? Wait, original row 1: \(Z=17\), \(A=17\)? Wait, no, original row 1: \(Z=17\), \(A=36\)? Wait, user's tabl…
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75. the illustration to the right shows a conservation of mass experime…
D. Some of the water molecules turned into gas and escaped the beaker ### Question 76
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16. which of the following describes the charge of alkali metals? a. it…
a. It has a 1+ ion charge.
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19. which of the following support the law of definite proportions? a. …
d. all of the above
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name_______________________________ period __________ date ____________…
(for row 1 as example, extend for others): Row 1: Atomic # = 17, Mass # = 36, \(p^+ = 17\), \(e^- = 17\), \(n^0 = 19\), charge = 0, Symbol = \(^{36}_{17}\text{Cl}\) (Repeat simila…
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which of the following is a property of a base? ○ slippery feel ○ turns…
A. slippery feel ### Second Question (Percent Yield Calculation)
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if you had a mixture of ag⁺, na⁺ and ca²⁺, how many different solids co…
1 (the option "1") ### Second Question (Charge on Co in $\boldsymbol{Co_2O_3}$)
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what type of reaction is the generic equation: ab + cd → ad +cb ○ decom…
double replacement/displacement (the option with this text) ### Second Question (Electron Configuration):
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question 51 (0.0862 points) group ia elements are also called ○ halogen…
D. alkali metals ### Question 52
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structure of poetry quick check if by rudyard kipling if you can talk w…
A. ABBACDDC (Wait, correction: The correct option is the one with ABBACDDC? Wait, let's re - analyze. Let's label the lines: Line 1: "If you can talk with crowds and keep your vir…
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what is a structural characteristic of a litany poem? (1 point) the sta…
B. Many lines or stanzas begin with the same word or phrase
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question 49 (0.0862 points) how many milliliters are in 1.75 l? \\( 1.7…
A. \( 1.75\times 10^{3} \) ### Question 50
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question 1 1 pts polyethylene and polypropylene are both types of what …
O plastic
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question 48 (0.0862 points) which substance is most likely to be miscib…
$\ce{NH3}$ (the option with $\ce{NH3}$)
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what is a quatrain? (1 point) ○ a type of poem with 14 lines ○ a group …
B. a group of four lines of poetry with the same rhyme scheme
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what is the aesthetic impact of a poem? (1 point) ○ how the poems speak…
B. how the poem affects the reader’s senses
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balance the equation $\\ce{c5h12o2 + o2 -> co2 + h2o}$ what is the coef…
7 ### Second Question (Miscibility with Water)
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structure of poetry quick check what is rhyme scheme? (1 point) ○ a set…
B. the ordered pattern of rhymes at the ends of lines of a poem
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question 45 (0.0862 points) the central atom in the nitrate ion has 3 s…
one double bond, 2 single bonds and no lone pair of electrons ### Question 46
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the lead chemist wants you to determine what is happening to the freedo…
The subfield is Chemistry (under Natural Science).
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question 43 (0.0862 points) how many moles of lithium nitrate are theor…
6.2 ### Question 44
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match the description with the terms. a. maximum amount of a substance …
a. 3. Solubility b. 1. Solute c. 2. Solvent
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value: 3 which of the following the pathway by which a chemical substan…
b. Biogeochemical cycle
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how many moles of iron are contained in 1.55 kg of iron? give the numbe…
\( 27.8 \, \text{mol} \) (or \( 27.7 \, \text{mol} \) depending on rounding; precise calculation: \( \frac{1550}{55.845} \approx 27.75 \), so 27.8 mol with 3 sig figs) ### Questio…
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question 38 (0.0862 points) considering the following precipitation rea…
\( \text{K}^+, \text{NO}_3^- \) (the option with \( \text{K}^+, \text{NO}_3^- \)) ### Question 39 (assuming the third option is "It contains a double bonded oxygen on a carbon tha…
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a 90.0g sample of nacl is dissolved in water to make a solution with a …
0.513 M (the option with 0.513 M) ### Second Question (Isotope symbol)
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what is the formula for calcium chlorate? cacl₂ caclo₂ caclo₃ ca(clo₃)₂…
D. \( \text{Ca(ClO}_3\text{)}_2 \) ### Second Question (State of Acetone at -96°C)
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ammonia gas decomposes according to the equation: $2\\ce{nh3}(g) \ ight…
36.0 L (corresponding to the option "36.0 L") ### Second Question (Nonpolar Molecule)
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question 30 (0.0862 points) what is the electron configuration of ge? k…
D. \([Ar]4s^2 3d^{10} 4p^2\) (assuming the options are labeled A, B, C, D in order as given) ### Question 31
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what is the final concentration of a solution prepared by diluting 25.0…
0.250 M ### Second Question (Functional Group)
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a solution at 25°c has a hydrogen ion concentration of 2.6 x 10⁻⁵ m. wh…
\([\text{H}_3\text{O}^+] > [\text{OH}^-]\) (the third option) ### Second Question (State of Matter)
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determine the empirical formula for a compound containing 40% carbon, 6…
B. $CH_2O$ ### Second Question (Physical/Chemical Changes)
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which solution below has the lowest concentration of hydroxide ions? ○ …
\( \text{pH}=3.21 \) ### Second Question (Isotopes)
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what is the main product when pa-233 undergoes alpha decay? u-233 u-235…
C. Ac-229 ### Question 21 (Gas Law Calculation)
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question: choose one polymer (dna, proteins, plastics, rubber, or nylon…
Plastics are useful in daily life for packaging (e.g., plastic bottles for storing liquids, protecting and preserving contents).
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question 18 (0.0862 points) how many neutrons are in cl-37? 17 37 35.35…
20 ### Question 19
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a lead ball has a mass of 75.0 g and a density of 11.4 g/cm³. what is t…
6.58 cm³ (the option with 6.58 cm³) ### Second Question (Mass Percent of Oxygen in Water)
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which term matches the definition: a covalent bond between atoms of dif…
B. polar covalent bond (assuming the options are labeled A: covalent bond, B: polar covalent bond, C: ionic bond, D: nonpolar covalent bond) ### Second Question (Naming the Molecu…
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examine the elements below and identify the one element that is from a …
P (the option with "P") ### Second Sub - Question (Number of isomers of \(C_5H_{12}\))
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question 10 (0.0862 points) which of the following statements is true f…
The pressure of a gas is due to collisions of the gas molecules. (The option with this statement) ### Question 11
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what is the molecular geometry of so₂? tetrahedral linear bent trigonal…
C. bent ### Second Question (Molecule with Hydrogen Bonding):
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why do oxygen atoms share electrons in o₂ instead of transferring them …
Oxygen atoms share electrons in $\ce{O2}$ (form a covalent bond) because they have similar electronegativities, and sharing 2 pairs of electrons (a double bond) allows both to ach…
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iodine-131 has a half-life of 8 days. how much of a 1000 mg sample woul…
125 mg ### Second Question (Significant Figures for Graduated Cylinder)
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part 1: phenomenon – why does salt taste salty? you eat a french fry sp…
B. Ionic bond
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how do atoms bond? standard: p.7.5c.6 - use the periodic table to make …
The relevant subfield is Chemistry (under Natural Science).
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question 1 (0.0862 points) how many valence electrons are in the nitrit…
18 ### Question 2
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value: 3 which of the following layers of the atmosphere where the mole…
b. Exosphere
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how do atoms bond? standard: p sc6 - use the periodic table to make pre…
B. Ionic bond ### Part 2 #### 1.
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warm-up why can i smell a chocolate bar even though it is a solid? read…
The office worker can smell the solid chocolate bar because all matter is made of tiny particles (atoms, molecules) that are in constant motion (kinetic theory of matter). The vol…
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a poem with fourteen lines and a mixed rhyme scheme is a foil couplet s…
D. sonnet
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put the liquids in order from most dense to least dense? 1,2,3,4; 4,3,2…
4,3,2,1
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a family is moving from pennsylvania to connecticut during the summer. …
For the second dropdown, the correct term should be "mechanical" (or "kinetic") instead of "potential" since the truck's movement involves kinetic (mechanical) energy from the con…
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read the paragraph from pams research paper. pam wants to add informati…
The fat globules create the smooth, creamy texture ice cream is known for.
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52. a process in which heat moves into the system is called a) endother…
A) Endothermic ### Question 53
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in the poems, how does shakespeare allude to, or refer to, ovids poem? …
by personifying time as cruel and destructive
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4. identify the appropriate block on the periodic table for each descri…
| Description | s - block | p - block | d - block | f - block | |--------------------------------------|-----------|-----------|-----------|-----------| | \( 1s^2 2s^2 2p^6 3s^2 3…
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4. identify the appropriate block on the periodic table for each descri…
D. Mendeleev
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3. sort the groups names and elements with the correct group number by …
- Group 1A: E (Alkali Metals) - Group 2A: B (Magnesium), H (Alkaline Earth Metals) - Group B: C (Iron), D (Transition Elements) - Group 7A: F (Halogens) - Group 8A: A (Krypton), G…
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calculator and the provided your answers on the provided akindi answer …
C) 250 m
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1. select one of the stockings to complete. they are all the same conte…
This is a set of instructions for a business - related project, likely falling under the Business discipline (subfields like Finance and Marketing could be relevant). The tasks in…
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label the diagram to show how hydrogen bonds form. a label may be used …
1. [+] 2. H 3. O 4. [-]
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Question was provided via image upload.
To identify the acids and bases in the reaction $\boldsymbol{\ce{H3C6H5O7 + H2O ightleftharpoons H3O+ + H2C6H5O7^-}}$, we use the **Brønsted - Lowry definition**: - An acid is a p…
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hydrochloric acid (hcl) - in water, it ionizes into ______ and cl⁻ ions…
### Hydrochloric Acid (HCl) Section: 1. In water, HCl ionizes into $\boldsymbol{H^+}$ (or $\boldsymbol{H_3O^+}$ is formed later, but the first ion from HCl ionization is $H^+$) an…
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practice: polyatomics name colin gray period 4 science directions: name…
1. Aluminum Nitrate (Correct formula name, original error fixed) 2. Iron(II) Chlorate (More precise, original was less specific) 3. \( \boldsymbol{\text{Be}_3(\text{PO}_4)_2} \) 4…
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measuring concentration molarity ______ is the amount of solute in a gi…
s: 1. Molarity of NaOH solution: \(\boldsymbol{10.0\space M}\) (corrected) 2. Grams of \(H_2SO_4\): \(\boldsymbol{588\space g}\) 3. Dilution equation: \(\boldsymbol{M_1V_1 = M_2V_…
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how much mass does the balance show? give numerical answers only. no un…
542.4
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essay: in the presence of sulfuric acid, one molecule of ethanol (c₂h₆o…
The unknown product has the formula \(C_2H_4\) (ethene). The technique is using the law of conservation of mass to balance the number of each element's atoms between reactants and…
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passage her shoes were white. and she had a long white veil dependent f…
by personifying time as cruel and destructive
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answer the following questions: 1. identify the element with the given …
Neon (Ne) ### Question 1b
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1. using an appropriate set of models, make molecular models of the com…
| Molecular formula | No. of bond pairs | No. of lone pairs | Hybridization of central atoms | Molecular geometry | Bond angle(s) | Dipole moment (yes or no) | |------------------…
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fill-in with the best word or phrase. 1. an electron has lower potentia…
1. closer 2. 3; 6 3. lowest; energy 4. n=1, s 5. lower; higher 6. Pauli Exclusion; 2; opposite 7. Aufbau; lowest; highest 8. Quantum Mechanical 9. 8 (He: 2) 10. principal quantum …
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1. nacl sodium chlorine 2. mgo magnesium monocgen 3. ca(no₃)₂ calcium n…
potassium carbonate (For sub - questions 5 - 12, the following are the answers: 5. \( \text{Al(OH)}_3 \): aluminum hydroxide 6. \( \text{CuCl}_2 \): copper(II) chloride (or cupric…
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matching 20 points match the vocabulary word with the definition. sun t…
- Sun: Source of energy for most of Earth’s inhabitants - Turbine: Energy harvested by allowing water to flow across a turbine in a dammed up river - Biofuel or biomass: Energy fr…
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balancing equations: balance the equation 30. ca(s) + h₂o(l) → ca(oh)₂(…
30. $\ce{Ca(s) + 2H2O(l) -> Ca(OH)2(aq) + H2(g)}$ 31. $\ce{2KClO3(s) -> 2KCl(s) + 3O2(g)}$ 32. $\ce{2Sb2S3(s) + 9O2(g) -> 2Sb2O3(s) + 6SO2(g)}$
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name __________________________________________ date ___________ block …
1. False, Correct: Atoms are most stable when their electrons are in the lowest possible energy state. 2. False, Correct: Bohr’s model accurately predicts energy levels for hydrog…
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matching 20 points match the vocabulary word with the definition. sun t…
- Finite resource: Resources that are limited and can’t be replaced because they take too long to form. - Renewable resources: Resources that can be replaced over time. - Biofuel …
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balancing equations: balance the equation 30. ca(s) + h₂o(l) → ca(oh)₂(…
30. $\boldsymbol{\ce{Ca(s) + 2H_{2}O(l) = Ca(OH)_{2}(aq) + H_{2}(g)}}$ 31. $\boldsymbol{\ce{2KClO_{3}(s) = 2KCl(s) + 3O_{2}(g)}}$ 32. $\boldsymbol{\ce{2Sb_{2}S_{3}(s) + 9O_{2}(g) …
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question 15 (1 point) the absolute temperature of an ideal gas is direc…
e) the average kinetic energy of its molecules
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balancing equations: balance the equation in t 30. ca(s) + h₂o(l) ⟶ ca(…
30. $\boldsymbol{\ce{Ca(s) + 2H2O(l) -> Ca(OH)2(aq) + H2(g)}}$ 31. $\boldsymbol{\ce{2KClO3(s) -> 2KCl(s) + 3O2(g)}}$ 32. $\boldsymbol{\ce{2Sb2S3(s) + 9O2(g) -> 2Sb2O3(s) + 6SO2(g)…
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explain or define the following: mixture vs pure substance heterogenous…
- Mixture vs Pure Substance: Pure substance (fixed composition, element/compound); Mixture (2+ substances, physical mix, variable composition). - Heterogeneous Mixture: Non - unif…