Chemistry
Chemical reactions, stoichiometry, molecular structures, and element properties.
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which of the following would help jamal to reason effectively? jamal is…
B. asking questions based on scientific knowledge (assuming the options are labeled with letters, if not, the option text is "asking questions based on scientific knowledge")
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short answer 1. how did the burning of modern materials like plastics a…
Burning plastics and electronics releases toxic chemicals (e.g., heavy metals, dioxins) into the dust. Ordinary fire debris has fewer such toxins, making 9/11 dust more dangerous …
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a small amount of americium-241 is used in smoke detectors. a stream of…
A. long half - life
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an article about half-lives describes a parent isotope. what is a paren…
D. an isotope that undergoes radioactive decay to form a more stable isotope
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isotope notation puzzle protons\tneutrons\telectrons\tatomic number\tma…
To solve the Isotope Notation Puzzle, we use the following relationships: - **Atomic Number (Z)** = Number of Protons (always). - **Mass Number (A)** = Protons + Neutrons. - **Net…
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1 which compound released from burning plastics is especially dangerous…
c) Dioxins ### Matching Questions 1. **Combustion**
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niobium-91 has a half-life of 680 years. after 2,040 years, how much ni…
18.75 g
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samarium-146 has a half-life of 103.5 million years. after 1.035 billio…
0.200 g
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what is a non-polar molecule? a. a molecule with a positive charge b. a…
d. A molecule with an even distribution of electrons
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which molecule is an example of a non-polar molecule? a. ammonia (nh₃) …
d. Methane ($\ce{CH_4}$)
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part b in a chemical reaction, substances react in a specific ratio. ch…
It is important for a company carrying out a chemical reaction to know the ratio of substances because: 1. **Efficiency**: It ensures the reaction proceeds completely, avoiding wa…
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what is a physical property of this yarn ball? the yarn ball is blue. t…
C. The yarn ball is pink. (Note: If the actual yarn ball in the image is of a different color among the options, the answer would change accordingly. But based on typical similar …
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which statement correctly compares chemical reactions with nuclear reac…
The correct statement is: "In chemical reactions, small amounts of energy can be absorbed or released. In nuclear reactions, changes in energy are much larger."
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the periodic table is arranged by various patterns. describe the patter…
Across a row (period) in the periodic table, the charge of ions formed by main - group elements shows a pattern. Metals on the left tend to lose electrons to form positive ions (c…
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which of the following molecules is symmetrical and non-polar despite h…
b. Carbon dioxide ($\ce{CO_2}$)
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section #1: history of the periodic table 1) who is attributed with the…
Dmitri Mendeleev ### Question 2
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question 2: analyze and extend part a explain whether changing the rati…
Changing the ratio of baking soda and vinegar does change the amount of carbon dioxide ($\ce{CO_{2}}$) produced. This is because the reaction $\boldsymbol{\ce{NaHCO_{3} + CH_{3}CO…
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an atom that has 84 protons and 86 neutrons undergoes a reaction. at th…
It emitted an alpha particle in a nuclear reaction.
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mixture: no mixture: yes atoms: 3 atoms: 8 elements: 2 elements: 3 mole…
To solve the problem of identifying compounds and mixtures, we analyze the left and right sections: ### Left Section (Mixture: NO) - **Atoms**: 3 (one zig - zag, two black). - **E…
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environmental and policy implications the chemical lessons of 9/11 push…
b) Fuel burns without enough oxygen, producing toxic byproducts ### Question 2
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molecules: compounds: mixture: image of three molecular structures (eac…
To solve the problem of identifying molecules, compounds, and mixtures (or other related counts like atoms, elements), we analyze the given diagram: ### Step 1: Identify Molecules…
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part d carry out the investigation you planned. record your data in the…
To complete this investigation, we can design a simple experiment by varying the amount of baking soda while keeping the amount of vinegar constant (or vice - versa) and observing…
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which of the following statements about secondhand smoke is not true? a…
C. Secondhand smoke is inhaled less deeply than firsthand smoke.
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group 2 elements have two valence electrons. which kind of bond will th…
D. An ionic bond is likely because they will want to give away two valence electrons in order to become stable.
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use the periodic table to answer the question. which statement correctl…
To solve this, we analyze the periodic table positions: - Francium (Fr) is in Group 1 (IA), so it has 1 valence electron. - Barium (Ba) is in Group 2 (IIA), so it has 2 valence el…
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on which atomic property proposed by henry moseley is the current perio…
A. atomic number
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atomic structure unit test what quality differentiates hydrogen (h) fro…
B. It is a non - metal
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3. calculate the theoretical yield in grams for this reaction. assume t…
The theoretical yield of alum is approximately \( \boldsymbol{8.79\,\text{g}} \) (depending on the exact molar masses used, but following the given values, this is the result).
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chem 1123 chapter 3: electromagnetic spectrum and periodic properties t…
The wavelength of the electron is approximately \(\boldsymbol{7.27\times10^{-11}\space m}\) (or \(72.7\space pm\)).
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part c list the amounts of baking soda and vinegar that you will use in…
Here is a sample list of combinations (holding baking soda constant at 1 tablespoon and varying vinegar): - Baking Soda: 1 tablespoon, Vinegar: 10 mL - Baking Soda: 1 tablespoon, …
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1. which of the following is the best example of a physical change? - b…
D. Melting of an ice cube
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part b now decide how many different combinations of baking soda and vi…
I will try 4 different combinations of baking soda and vinegar. (Note: Any number ≥3 is acceptable, e.g., 3, 4, 5, etc. The answer can be adjusted as per preference as long as it …
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case study excerpt: chemical analysis of wtc dust in the months after 9…
The dust had a high pH because it contained pulverized concrete and gypsum from drywall (these materials have alkaline - forming components). This highly alkaline dust could burn …
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1. read the passage which describes aspects of the behavior of gases. s…
expand, increased, more, compressibility (the option with this list, likely the third option as marked in the image: "expand, increased, more, compressibility")
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a meteorologist is measuring air samples (a gas sample) taken from diff…
The option stating: *"The air sample from the mountaintop would be less dense. The lower pressure at the mountaintop means that the molecules would be further apart. Therefore, fe…
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question 1: planning and data collection part a this investigation is a…
I choose to change the amount of baking soda. Reason: Baking soda is a solid, so its mass can be precisely measured and controlled to manipulate the reaction (between baking soda …
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1 a sample of oxy... volume of 2 l is compressed to a volume of 1 l. ba…
The option (assuming the third option in the list, with text "The number of collisions and the pressure both increase"): The number of collisions and the pressure both increase.
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which parts of the fuel cell do a and b represent? air anode and cathod…
B. anode and cathode
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which limitation of fuel cells is the most likely reason why people are…
A. Hydrogen gas is volatile
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determine which characteristics of a chemical change each example shows…
To solve this, we analyze each example: ### 1. Popping an Inflated Balloon - **The chemical makeup of the substance changes?** No (just a physical change in shape/volume of the ba…
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| | popping an inflated balloon | dissolving sugar in water | mixing vi…
To solve this, we analyze each process: ### 1. Popping an Inflated Balloon - **Physical change**: Popping a balloon only changes its shape/state (no new substance, chemical makeup…
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what is the purpose of finding oxidation states in the half-reaction me…
B. to identify the half reactions for the equation
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consider the redox reaction below. zn(s) + 2hcl(aq) ——→ zncl₂(aq) + h₂(…
B. $\ce{Zn(s) -> Zn^{2+}(aq) + 2e^-}$
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which equation describes a reduction? ○ mg(s) ⟶ mg²⁺(aq) + 2e⁻ ○ 2cl + …
B. \( 2\text{Cl} + 2\text{e}^- \longrightarrow 2\text{Cl}^- \)
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consider the half reaction below. cu²⁺(aq) + 2e⁻ ⟶ cu(s) which statemen…
B. Copper is being reduced.
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a student is asked to balance an equation by using the half - reaction …
A. $\ce{Cl_{2} + 2Br^{-} -> Br_{2} + 2Cl^{-}}$
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based on the information in the table, which two elements are most like…
bismuth and nitrogen, because they have the same number of valence electrons
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which statement is true of the following reaction? h₂ + o₂⟶h⁺ + o²⁻ it …
It is not balanced for oxidation state or for number of atoms.
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unit 3 matter interactions > lesson 5 physical vs. chemical change mark…
To solve this, we analyze each example based on physical and chemical change concepts: ### 1. Popping an Inflated Balloon - **A physical change occurs**: ✔️ (Popping a balloon is …
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part of one row of the periodic table is shown. which elements atoms ha…
tellurium (Te)
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how many groups are in the modern periodic table? ○ 12 ○ 18 ○ 22 ○ 24
B. 18
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consider the redox reaction below. mg(s) + fe²⁺(aq) → mg²⁺(aq) + fe(s) …
A. $\ce{Fe^{2+}_{(aq)} + 2e^- \longrightarrow Fe_{(s)}}$
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this is how krypton appears in the periodic table. 36 kr krypton 83.80 …
A. 36
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which half-reaction correctly describes an oxidation? ○ ca(s) + 2e⁻ ⟶ c…
D. $\ce{Cr(s) -> Cr^{3+}(aq) + 3e^-}$ (assuming the last option is D, if options are labeled A - D with the last one as D)
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which is an important step in the alternate method for balancing equati…
C. determining the half reactions of chemical equations
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while looking at calcium (ca) on the periodic table, a student needs to…
directly to the right
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which two chemists organized elements based on properties such as how t…
D. Lavoisier and Döbereiner
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what are 1a, 3b, and 7a examples of on the periodic table? ○ groups. ○ …
A. groups.
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which describes the oxidizing agent in a chemical reaction? the substan…
D. the substance that is reduced because it gains electrons
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consider the following reaction. co₂(g) + h₂(g) ——→ co(g) + h₂o(l) what…
D. hydrogen
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elements in group 2 are all called alkaline earth metals. what is most …
B. which chemical properties they have
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what is the oxidation number for s in the compound so₃? (recall that o …
+6
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which best describes the oxidizing agent in this reaction? cl₂(aq) + 2b…
C. Chlorine (Cl) is the oxidizing agent because it gains an electron.
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dmitri mendeleev and henry moseley developed their periodic tables abou…
C. The number of protons in an atom is different than the atom’s total mass. (Note: The option description might have a slight wording issue, but the core idea is that the number …
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which type of reaction occurs in the following? 2hgo(s) → 2hg(l) + o₂(g…
a decomposition reaction in which a metal is reduced
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which answer best describes what is happening in the following reaction…
B. This is a redox reaction in which octane ($\ce{C8H18}$) is the reducing agent.
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the element phosphorus is located to the right of the element magnesium…
Phosphorus has a larger atomic mass.
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the presence of which reactant is the best indicator of an oxidation-re…
D. $\ce{H_{2}}$
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which identifies an oxidation-reduction reaction? a double replacement …
C. a reaction in which oxidation numbers change
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which best identifies why the rusting of an iron nail in the presence o…
B. Electrons are transferred.
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naming molecular compounds and acids: provide the correct name or chemi…
$NO$ ### 2. $\boldsymbol{N_2O_5}$
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given the reaction below, which is being reduced? mg + cl₂ ⟶ mg²⁺ + 2cl…
B. $\ce{Cl_{2}}$
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name: name: period: matter vocabulary matching cut off the column of vo…
To solve this matter vocabulary matching, we analyze each definition and match it with the correct term: 1. **Matter that flows but has a definite volume** → Liquid (liquids flow …
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naming ionic compounds: provide the correct name for the following chem…
Magnesium bromide ### 2. $\boldsymbol{Cr_2S_3}$
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a 1.00 l volume of hcl reacted completely with 2.00 l of 1.50 m ca(oh)2…
6.00 M
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a number of beakers have different concentrations of a solution. which …
It has the most solute for a given volume.
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a solution of hcl has h⁺ = 0.01 m. what is the ph of this solution? use…
2
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which of these correctly defines the poh of a solution? the log of the …
D. the negative log of the hydroxide ion concentration
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what is the name of a solution whose concentration of solute is equal t…
B. saturated
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soaps feel slippery on our hands because they dissolve the oil on our s…
D. a base
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the table below shows four samples of carbon dioxide gas and the temper…
1 (Sample 1)
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what should this mixture be classified as? colloid compound solution su…
D. suspension
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an unknown substance turns blue litmus paper to red. which additional t…
D. It should turn methyl orange to red because it is an acid
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jacob’s journey through canaan genesis 33:16-36:43 a. the journey begun…
To solve these questions, we refer to the specified Bible verses (Genesis chapters 33 - 35) for each sub - question: ### Part A: The Journey Begun (Genesis 33:16 - 34:31) 1. **Que…
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which heterogeneous mixture contains large particles that can settle ou…
D. suspension
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which is true about the dissolving process in water? ○ polar solutes do…
B. Water molecules are attracted by solute ions at the surface of the solute
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what type of mixture scatters light and cannot be filtered easily? ○ a …
a colloid, a heterogeneous mixture
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which statements are true of heterogeneous mixtures? 1) they settle out…
1 and 2
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which factor causes a decrease in the rate of dissolution? ○ decreasing…
C. decreasing the surface area of the solute
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depends on the type of matter in a sample matter that takes both the sh…
To solve this matching problem, we analyze each term and its definition: 1. **Extensive Property**: Depends on the amount (type/amount) of matter in a sample. 2. **Plasma**: Highl…
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lesson review 1. which of these is not made up of two or more substance…
B. compound ### Question 2
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which of the following is the correctly balanced chemical equation for …
D. $\ce{Ca(OH)_{2} + 2HNO_{3} ightarrow 2H_{2}O + Ca(NO_{3})_{2}}$
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which description correctly characterizes the acidity or basicity of a …
B. The higher the pH is, the more the hydroxide ion concentration increases and the more basic the solution becomes.
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which pair of substances would most likely result in the production of …
C. metal and carbonate
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which of the following substances is an arrhenius acid? ○ bf₃ ○ hcn ○ n…
B. HCN
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a solution of ammonia has a ph of 11.8. what is the concentration of oh…
\(6.31\times10^{-3}\ M\)
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question 14 zinc metal can be flammable. true false
A. True
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given that the molar mass of nacl is 58.44 g/mol, what is the molarity …
3.00 M
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question 13 1 pts modern pennies are made completely out of copper. tru…
False
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lewis acids and bases are most closely associated with which process? ○…
B. electron transfer