Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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5. how many minutes are in two days? 2,880 minutes .00139 minutes 5 min…
2,880 minutes (the first option)
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dangerously reactive oxidizer other toxic effects biohazard 28 a flamma…
False ### Question 29
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2. what is the resulting unit from the calculation shown below? ( 10 \t…
A. ft
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valence electrons 1 quick check two representative elements, nitrogen a…
A. They have valence electrons in the same energy level
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1. how many grams are in 562 dg? 56.2 g 5.62 g 5,620 g 56,200 g
56.2 g (the option with "56.2 g")
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how many valence electrons does each atom of arsenic (as) have? arsenic…
5 (corresponding to the option with "5")
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the ph scale coffee egg white soda water ammonia solution 43. a 3 b 5 c…
The hydroxide ion concentration is equal to the hydrogen ion concentration in water.
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41 directions select all the correct answers. which are the products in…
$\ce{Cu(NO_{3})_{2}(aq)}$, $\ce{2Ag(s)}$
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40. a chemical reaction that causes the mixture to feel cold is an exam…
B. absorbed (assuming the option with "absorbed" is labeled as B, if the original options had labels like A, B, C, D, we use the correct label. From the options, the one with "abs…
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26. which of the following equations is an endothermic reaction? - $ce{…
The equation for the endothermic reaction is $\boldsymbol{4\ce{CO_{2}(g)} + 6\ce{H_{2}O(l)} ightarrow 2\ce{C_{2}H_{6}(g)} + 7\ce{O_{2}(g)}}$ with $\Delta H = +3120\ \text{kJ}$.
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25. which of the following shows the behavior of an arrhenius acid? opt…
$\boldsymbol{\ce{HF -> H+ + F-}}$ (the option with this reaction)
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33. directions drag and drop the correct answer choice to each answer b…
First blank: unsaturated solution Second blank: saturated solution Third blank: supersaturated solution
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21. phosphoric acid (h₃po₄) is a weak acid primarily because it... opti…
gives up to three protons to a solution
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31. for two bases of equal concentration, the weaker base has — a lower…
A. a lower concentration of hydroxide ions.
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participants in a study are divided into two groups. one group receives…
C. experimental
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which element does not have the same number of electrons in its outermo…
Helium (He)
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potassium’s atomic number is 19, and its atomic mass is approximately 3…
20
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which of the following defines the atomic number of an atom? (1 point) …
A. the number of protons (assuming the first option is labeled A, adjust label as per original if different, but based on content, the correct choice is the option stating "the nu…
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which element has six valence electrons? (1 point) oxygen (o) carbon (c…
A. oxygen (O)
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stable ions quick check which property do the elements in each column o…
number of valence electrons
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protons: 14 neutrons: 15 electrons: 14
If the problem was to find the mass number, the answer is 29. (If the actual problem was different, for example, identifying the element (which would be Silicon, as atomic number …
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30. fill in the blanks with the correct options. when calculating the m…
To solve this, we recall the formula for molarity ($M$): The formula for molarity is $M = \frac{n}{V}$, where $n$ is the number of moles of the **solute** and $V$ is the volume (i…
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protons: 7 neutrons: 8 electrons: 10 0 ▲▼ 3− n 7 nitrogen
15 (If the problem was different, e.g., finding charge or something else, adjust accordingly. Since the problem wasn't specified, a common calculation here is mass number.)
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protons: ● neutrons: ● electrons: ●● 2 0 h 1 hydrogen (with atomic mode…
This represents a hydride ion (\( \text{H}^- \)) of the deuterium isotope (mass number 2) of hydrogen, with 1 proton, 1 neutron, and 2 electrons.
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use solubility rules to determine the missing states of matter in the e…
C. \( NH_4OH \) (assuming the options are labeled as A: \( (NH_4)_2Cr_2O_7 \), B: \( Ca(OH)_2 \), C: \( NH_4OH \), D: \( CaCr_2O_7 \))
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protons: 16 neutrons: 17 electrons: 16 33 s 16 sulfur
The mass number of this sulfur atom is 33.
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choose the correct liquid on the graph by selecting the appropriate box…
(Example, if identifying Water) Water (the blue - colored curve on the graph, as its vapor pressure equals 101.3 kPa at 100°C, its boiling point). (Note: The exact answer depends …
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calculations using significant figures when multiplying and dividing, l…
\( 3.33 \, \text{m}^2 \) ### Problem 2: \( 1035 \, \text{m}^2 \div 42 \, \text{m} \) (assuming 1,035 is 1035)
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25. a sample of hydrogen gas occupies 3.0 l at 960 torr in a balloon. i…
960 torr(3.0L)/760 torr (the option with this expression)
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protons: 16 neutrons: 17 electrons: 16 33 0 s 16 sulfur
The mass number of this sulfur atom is 33.
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multiple-choice question ture or false all chemicals can be poured down…
False (the option "False" should be selected, i.e., the checkbox next to "False" should be marked)
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34. which of the following is true of a limiting reagent? select two an…
A. It is a reactant, B. It limits the amount of product formed
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protons: (red circle), neutrons: (gray circle), electrons: (dotted circ…
The number of electrons is 1. (If the question was different, for example, number of neutrons: 1, protons: 1. But based on the diagram and the element (hydrogen, atomic number 1, …
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multiple-choice question before leaving the class on a day when we have…
A. Have the teacher check if your table/area is clean and is okay for you to leave B. Put the chemicals back into the original containers C. Make sure all the equipment and materi…
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23 choose the type of reaction for each equation. a + b ⟶ ab is for – c…
- \( A + B ightarrow AB \) is for synthesis reactions. - \( AB ightarrow A + B \) is for decomposition reactions. - \( AB + C ightarrow AC + B \) is for single - replacement (sing…
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multiple-choice question the best way to identify an unknown chemical o…
C. Reading the label
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22. what is the balanced equation for the formation of rust if four mol…
B. $4 \text{ Fe (s)} + 3 \text{ O}_2 \text{ (g)} ightarrow 2 \text{ Fe}_2\text{O}_3 \text{ (s)}$
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21. in the chemical reaction below, what are the correct coefficients? …
The coefficient for $AgNO_3$ is 2 and the coefficient for $Ag$ is 2. So the blanks should be filled with 2 (for $AgNO_3$) and 2 (for $Ag$) respectively.
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multiple-choice question a safe way to smell chemicals in a lab is by -…
A. wafting to bring the smell to you through the air
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20. consider the following balanced chemical equation: 4fe + 3o₂ → 2fe₂…
The total number of atoms stays the same because atoms are rearranged but not created or destroyed.
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etermine the number of significant figures in each number. 1. 0.02 ____…
To determine the number of significant figures, we use the rules: - Leading zeros (zeros before the first non - zero digit) are not significant. - Non - zero digits are always sig…
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when gathering glassware and equipment for an experiment, you should: s…
- Examine all glassware to check for chips or cracks, if there are any do not use it - Read all directions carefully to know what equipment and glassware is necessary - Inform you…
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18. how many nitrogen particles are present in 1.00 mole of methane, nh…
\(6.02\times 10^{23}\) (corresponding to the option with \(6.02\times 10^{23}\))
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18. which of the following will result in 1.00 mole of calcium chloride…
The correct option is the one with \(6.02\times10^{23}\) ions of \(Ca^{2+}\) and \(1.20\times10^{24}\) ions of \(Cl^-\) (the second option in the list).
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what point does the author make about how the categories of legal and i…
The classification of which drugs are legal or illegal is out of habit rather than chemical or physiological standards.
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d) instrumentation answer: d 22. why is piping considered fixed equipme…
22. B) Because the pipe itself doesn't move 23. B) Pipe in a chemical plant 24. D) Instrumentation 25. B) A water treatment system
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multiple-choice question if glassware should break, which of the follow…
A. Broken glass goes in a special container B. Tell the teacher immediately
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which of the following will result in 1.00 moles of calcium chloride, c…
\(6.02\times 10^{23}\) ions of \(Ca^{2+}\) and \(1.20\times 10^{24}\) ions of \(Cl^-\) (the second option)
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multiple-choice question during lab days, the following should not be w…
A. Sandals or other open toe shoes like crocs, C. Dangling long jewelry
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section 2.4 chemical reactions 1. which one of the following is a chemi…
1. c. gasoline burns 2. a. physical b. chemical c. chemical d. physical 3. yields (or produces) 4. carbonic acid 5. carbon dioxide, water 6. 62 grams 7. 32.4 grams 8. Law of Conse…
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12. which of the electron dot structures correctly illustrates diatomic…
The first option (the top - most option with the structure $\boldsymbol{\cdot \cdot N\colon \colon \colon N\cdot \cdot}$ (represented by the dots as in the first choice) is the co…
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multiple-choice question gloves must be worn in labs that involve paper…
C. Chemicals or materials that could irritate or burn your skin
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17 which of the electron dot structures correctly alternates diatomic n…
The top - most option (the one with the structure $\boldsymbol{\cdot \overset{\cdot \cdot }{\underset{\cdot \cdot }{N}} \; \vdots \; \vdots \; \overset{\cdot \cdot }{\underset{\cd…
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l1 - $300 question when atoms of one element combine with atoms of othe…
C. substances
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complete the statement below about the electron dot structure of the co…
This compound is created by transferring an electron, which is called an $\boldsymbol{ionic}$ bond. This compound's name is $\boldsymbol{sodium\ chloride}$.
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multiple-choice question approved eye protection devices such as goggle…
B. Any time chemicals, heat, or glassware are used
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multiple-choice question true or false even if you wear glasses, you sh…
True
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the following best describes a property of covalent compounds? they hav…
The option "They typically have low melting and boiling points because the forces between molecules are weak."
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multiple-choice question what can prevent glass and other materials fro…
A. Keeping a clean work space, B. No horseplay
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14. what is the correct iupac name for the compound with the formula h₂…
A. dihydrogen monoxide
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adsorb mean to attach and absorb mean to soak in. true false
True
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13. carbon dioxide is a very commonly used covalent compound. what is t…
B. \( CO_2 \)
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13. carbon dioxide are only commonly used in some purpose. what is the …
The correct option (assuming the second option is \( \text{CO}_2 \)): B. \( \text{CO}_2 \) (or the option label corresponding to \( \text{CO}_2 \) in the original question's choic…
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the atomic number of elements in the periodic table ____ as you go from…
A. INCREASE
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is the name of the binary compound for the formula bacl₂?
barium chloride
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chapter 2: culture & construction page(s) 42-43 2.1. explain the concep…
First blank: the symbolic structure Second blank: binaries Third blank: signifiers
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11 which of the following periodic trends is most useful in predicting …
B. electronegativity
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l1 - $1000 questions matter is a. partially visible b. partially visible
B. anything that has mass and takes up space (assuming the option text is this, based on the standard definition of matter)
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what is the name of the binary compound for the formula ki? move the co…
potassium iodide
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which characteristics of dickinson’s style are evident in \the snow\? s…
A. four - line stanzas C. a varying rhythm D. the use of personification
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name 4. which of the following are pure substances? which are mixtures?…
4. Pure substances: a. ethanol, d. helium; Mixtures: b. vinegar, c. motor oil 5. (Assuming Table 2.3 has solution types like aqueous, solid - solution, etc.): a. ethanol in water:…
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which statement best describes the rhyme scheme of a thought on the ine…
There is an absence of a clear rhyme scheme.
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3. what is an electron configuration? options: - a description of where…
The correct option is: a list of where all the electrons are located in an atom (the fourth option).
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what is an electron configuration? a description of where valence elect…
The correct option is the one with "a list of where all the electrons are located in an atom" (the fourth option in the list of choices).
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read the poem oses,\ by george eliot. you love the roses—so do i. i wis…
B. "Night" uses a rhyme scheme.
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a tamoxifen study claims that a combination of chemotherapy and the hor…
the first group of 361 that received tamoxifen alone ### Second Sub - Question (Study Type - Blinding)
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the mass of which particle is disregarded when determining the mass of …
D. electrons
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any atom that is electrically neutral must contain... more protons than…
The correct option is the one with "equal numbers of electrons and protons". (Assuming the first option's text was a typo and the intended correct option is "equal numbers of elec…
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7 based on the periodic table, which of the following propositions is m…
B. Halogens have seven valence electrons and are highly reactive, especially with alkali metals, to form salts.
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which particles are used to determine the mass number of an isotope? o …
C. protons and neutrons
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3. which statements of the following best explain why the noble gases b…
- Noble gases have large atomic radii - Noble gases have a full outer shell of electrons - Noble gases are neutrally charged
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5. which of the following statements correctly describes the properties…
A. Alkali metals in Group 1 have one valence electron and are very reactive
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read shakespeare’s \sonnet 19.\ devouring time, blunt thou the lion’s p…
- the widespread use of iambic pentameter - the use of three quatrains followed by a couplet - the fact that the final lines summarize the preceding lines
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exam 1 8. an experiment revealed the empirical formula of a compound to…
c) \( C_3H_6 \) ### Question 9
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4. which of the following best describes the process by which the moder…
The option: "The elements were originally arranged by atomic mass, but later, they were rearranged by atomic number to reflect recurring chemical properties." (the first option am…
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voice level = 1 (purr aka whisper!) wer both multiple-choice questions …
B. 98 g
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3. what are some characteristics of alkali metals? select two correct a…
C. Alkali metals are highly reactive and good conductors of electricity, E. Alkali metals have a single electron in the outermost shell
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in chemistry, the concept of a mole is fundamental for quantifying the …
A. A mole is used to relate the amount of a substance to its mass, where the mass is determined based on the substance’s molecular or atomic weight.
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which words create the rhyme scheme in the second stanza? \wild call\ a…
"tide" and "denied"
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use the drop-down menus to answer the questions about john masefield’s …
three ### For the second question "What is the rhyme scheme of the first stanza?":
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clearly mark the letter of the best answer for questions 1 – 15 on the …
c) \(^{17}\text{O}^{2-}\) ### Question 2
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to improve the safety of your location and comply with regulations rega…
D. Download them from the chemical manufacturer’s websites.
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use the drop-down menus to answer the questions about jo masefields poe…
- How many stanzas are in the poem? 3 - What is the rhyme scheme of the first stanza? AABB - What poetic structure does Masefield use? Quatrains (with iambic tetrameter and repeat…
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section 2.2 mixtures 1. how might one separate a mixture of water and s…
One can separate a mixture of water and salt by evaporation (heating the mixture to vaporize the water, leaving salt behind) or distillation (collecting and condensing the water v…
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i. multiple choice: encircle the letter of the correct answer. 1. which…
C. Form ### Question 2
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physical state | definite shape? | definite volume? | readily compressi…
One can separate a mixture of water and salt by evaporation. Heat the salt - water solution; the water will evaporate as vapor, leaving the salt behind. (Distillation can also be …
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5. complete the following table. | physical state | definite shape? | d…
To complete the table, we recall the properties of the three physical states (solid, liquid, gas): ### For Gas: - **Definite shape?**: No (gases take the shape of their container)…
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practice problems in your notebook, solve the following problems. secti…
b. burning gasoline in an engine ### Question 2
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draw the lewis structure for the methane (ch₄) molecule.
The Lewis structure of \( \text{CH}_4 \) has a central carbon atom bonded to four hydrogen atoms via single covalent bonds. The structure is represented as: ``` H | H - C - H | H …
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elements in order of the trend. numbers based on trends. may also selec…
s (Key Points) - Valence electrons: Ca: $2$, F: $7$, Si: $4$, Ar: $8$ - Oxidation numbers: Rb: $+ 1$, Al: $+ 3$, Te: $- 2$, Sn: $+ 4$ - Elements by location: 1. Ta, 2. S, 3. Ti - …