化學
化學反應、化學計量、分子結構與元素性質。
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question 1 - 1 coins in the united states are made from a variety of me…
The coins will turn green faster (increased reaction rate due to heating), and algae (if present) may not survive in hot temperatures (depending on their heat tolerance). So the c…
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the osmotic pressure of a dilute solution depends on which of the follo…
molarity, the gas constant, temperature.
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question what is the osmotic pressure (in atmospheres) of a 0.750 m sol…
$18.5$
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what is the osmotic pressure of a 0.25 l solution that contains 0.88 g …
0.69 atm
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what is the concentration of a sodium chloride solution that exerts an …
0.284 M
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question in the dilution equation, which of the following can be expres…
volume
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when diluting a solution, which of the following changes? select all th…
solution volume, solution concentration, volume of solvent
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question a professional chef thins a sauce for a particular dish using …
dilution
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which of the following will decrease the concentration of a solution? s…
adding more solvent, removing moles of solute
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what is the percent mass of 4 g of c₁₂h₂₂o₁₁ in 350 ml of water? select…
\(1.13\%\) (the third option)
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a solution is made by adding 15 g of sodium chloride into 150 g of wate…
9.09%
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what is the percent mass of 61 g of calcium chloride in a 205 g solutio…
\(29.8\%\) (the third option)
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select all that apply which of the following have been investigated as …
A. A smaller area 25, B. Chemical deficiencies in the brain, D. An overreactive autonomic nervous system
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the chemical symbol for the element calcium is ca. what would be the sy…
\(Ca^{+2}\)
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what is the number at the end of an isotopes name? atomic number neutro…
mass number
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which are different forms of an element that have different numbers of …
Isotopes.
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a potassium atom (atomic number 19) loses an electron while forming a b…
It is a positive ion that has one less valence electron than a neutral potassium atom.
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all large radioactive atoms decay into smaller atoms by releasing alpha…
helium - 4
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atoms of the element potassium have 19 protons. one of the most stable …
20
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use the image to complete the statements. the aluminum atom electrons t…
The aluminum atom loses electrons to form an ion. The ion that is formed is \(Al^{3 +}\).
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use the drop - down menus to complete the statements. when electrons ar…
When electrons are lost, a cation ion is formed. When electrons are gained, an anion ion is formed.
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an isotope of the element fluorine has 9 protons and 10 neutrons. what …
fluorine - 19
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use the drop - down menus to complete the statement. an isotope has the…
An isotope has the same number of protons but a different number of neutrons than other atoms of the same element.
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use the drop - down menu to complete the statement. an electron in the …
a lower energy than
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the element copper has 29 protons. what is the atomic number of copper?
29
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which statement accurately describes the chemical symbol of an element?…
The chemical symbol always begins with a capital letter.
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use the drop - down menu to complete the sentence. when 1 carbon atom c…
compound
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use the drop - down menu to complete the statement. an element is made …
one type of atom
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5. a student finds a gray metal sample and claims it is aluminum. which…
A. Measure its density and compare it to aluminum's known density
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4. lariyah is completing a lab in which she is required to identify an …
A. density
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3. diontes teacher has given him a sample that contains a mixture of sa…
C. magnetism
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which statement below best explains what happened? compounds are broken…
Atoms of different elements combine to form compounds.
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question 1 - 8 pure substances can consist of both elements and compoun…
Elements combine to form a compound.
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atoms combine to form different types of substances. some examples are …
A. C, and D are pure substances; B is a mixture
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1. which statement is true of all matter? a. it has mass b. it can be s…
A. It has mass
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the following ph levels were found for four different liquids which of …
Lemon Juice
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question 5 of 9 submit test sci_phys_cfa3_classifyingmatter_5120 2 pure…
Bleach should be identified as a base.
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sodium chlorine sodium chloride (diagram is not drawn to scale) which s…
Sodium chloride is a compound.
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question 1 - 2 the primary dissolved gases in water are oxygen (o₂), ni…
homogeneous mixture
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an epipen is an epinephrine autoinjector for anaphylaxis. what is the m…
$2.1\%$
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question 1 - 1 lika is asked label a set of models to describe mixtures…
B
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solubility is determined by: select the correct answer below: solute - …
all of the above
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which of the following best describes the term \saturated\? select the …
"Saturated" describes a solution with a solute concentration equal to its solubility value.
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which statements correctly explain what could increase the likelihood o…
- Gas particles collide with enough energy to satisfy the activation energy, which kick - starts the reaction. - Atoms have incomplete valence shells, which means that the atoms a…
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what are the products that are formed when ag reacts with h₂s in a sing…
\(\text{Ag}_2\text{S and H}_2\) (the third option)
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read the statement. in your car engine, octane (c₈h₁₈) undergoes a comb…
\(2C_8H_{18}+25O_2 ightarrow18H_2O + 16CO_2\)
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note: to answer some of the questions, it may help to reference a perio…
\(MgCO_{3}\to MgO + CO_{2}\)
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pb(oh)₂ reacts with hcl in a double - displacement reaction, what is th…
\(Pb(OH)_2+2HCl ightarrow 2H_2O + PbCl_2\) (the fourth option)
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which of the following is equal to the solubility of a solute in a part…
- The maximum equilibrium concentration of solute that can be achieved. - The concentration of solute in a saturated solution.
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the maximum concentration that a solution can achieve with respect to a…
C. solubility
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its time for the unit exam. this is your opportunity to show how if you…
1, 1, 3, 1
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of the following, which are characteristics of weak electrolytes? (sele…
- They produce a low concentration of ions when dissolved in water. - They are soluble in water. - They exhibit low conductivity.
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its time for the unit exam. this is your opportunity to show how if you…
1, 1, 1
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its time for the unit exam. this is your opportunity to show how much y…
\(2S + 3O_{2}\to 2SO_{3}\)
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question which type of substance will conduct the most electricity? sel…
strong electrolyte
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which would conduct electricity best? select the correct answer below: …
C. ocean water
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its time for the unit exam. this is your opportunity to show how much y…
\(N_2S_3\) (the third option)
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its time for the unit exam. this is your opportunity to show how much y…
iron(III) sulfide
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0.090 moles of sodium sulfate is dissolved in a 12 ml solution. what is…
7.5
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its time for the unit exam. this is your opportunity to show how much y…
\((NH_4)_2SO_4\)
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what is the oxidation state of each element in aluminum hydroxide (al(o…
\(Al^{+3};H^{+1};O^{-2}\) (First option)
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0.30 moles kbr is dissolved in 0.15 l of solution. what is the concentr…
2.0
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its time for the unit exam. this is your opportunity to show how much y…
an ion made up of two or more atoms covalently bonded
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its time for the unit exam. this is your opportunity to show how much y…
diphosphorus pentoxide
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its time for the unit exam. this is your opportunity to show how much y…
The cation is written before the anion in the name and formula of an ionic compound.
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what is the molarity of a 2.4 l solution with 1.2 moles of nitric acid …
0.50
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its time for the unit exam. this is your opportunity to show how much y…
when it has two different elements bonded together
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120 grams of calcium nitrite ca(no₂)₂ is dissolved in a 240 ml solution…
\(3.8\space M\)
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its time for the unit exam. this is your opportunity to show how much y…
A molecular formula will show the actual number of atoms in a molecule, while the structural formula will show the organization and layout of the atoms in the compound.
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its time for the unit exam. this is your opportunity to show how much y…
chemical formula
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homework: balancing chemical equations and identifying the reaction typ…
1. \(2C_2H_6+7O_2 ightarrow4CO_2 + 6H_2O\), Combustion 2. \(8Fe+S_8 ightarrow8FeS\), Synthesis 3. \(H_2CO_3 ightarrow CO_2 + H_2O\), Decomposition 4. \(3AgNO_3+Al ightarrow Al(NO_…
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question 6 1 point in the reaction below, cl⁻(aq) is the enter answer a…
\(Cl^{-}(aq)\) is the reducing agent and \(I_{2}(g)\) is the oxidizing agent.
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question 5 1 point select the correct net ionic equation for the equati…
A. \(Cu^{2+}(aq)+S^{2 - }(aq)\to CuS(s)\)
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model 2 - ion charges for selected elements 10. draw a stair - step lin…
a. Nonmetals form anions. b. Metals form cations. c. Hydrogen (\(H\)).
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what color does cobalt - oxide produce? a. blue - violet b. red c. yell…
A. blue - violet
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what is cobalt oxide? a. a chemical element b. a chemical compound c. a…
B. a chemical compound
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which term describes a pure substance that is made up of only one type …
element
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the most abundant element in the atmosphere can also be found in fruits…
beans and whey protein.
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which substance is a compound? hydrogen gold oxygen water
water
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which statement correctly describes glucose (c₆h₁₂o₆)? it is an element…
It is a compound made of twenty - four total atoms.
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students are each given a 20 - gram sample of an unknown solid compound…
Each piece contains the same proportion of different elements.
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what is the basic unit of matter? gas molecule compound atom
atom
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which of these elements is found in both carbohydrates and water? heliu…
Oxygen
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what is the primary function of the carbon cycle? creating fossil fuels…
recycling the supply of carbon on Earth
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ionic bonds name the following ionic compounds (rule 1 and 2): 1. nabr …
11. \(KI\) 12. \(MgO\) 13. \(AlCl_{3}\) 14. \(NaNO_{3}\) 15. \(CaCO_{3}\) 16. \(Li_{2}SO_{4}\) 17. \(Be_{3}P_{2}\) 18. \(Mg(OH)_{2}\) 19. \(Co_{3}N_{2}\) 20. \(CrF_{2}\) 21. \(Na_…
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choose the correct answer for each question. use the col 1. the repetit…
1. Assonance 2. Stanza 3. Haiku 4. Limerick 5. Sonnet 6. Ballad 7. Diction 8. Ode 9. Slant rhyme 10. Metaphor
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model 1 - eggs chicken\t\t\tquail\t\tratio of\tratio of number of eggs\…
| Chicken | | Quail | | Ratio of numbers of eggs | Ratio of masses of eggs | |--|--|--|--|--|--| | Number of eggs in the sample | Mass of the sample | Number of eggs in the sample…
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examine the chemical equation. check the box(es) for the specific indic…
precipitate formation
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___c₆h₁₂o₆ + ___o₂ → ___h₂o + ___co₂
\(1C_6H_{12}O_6+6O_2 ightarrow6H_2O + 6CO_2\)
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what type of reaction is bf₃ + li₂so₃ → b₂(so₃)₃ + lif? synthesis singl…
None of these
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isotopes worksheet 1. what is an isotope? 2. what does the number next …
1. Atoms of the same element with different neutron numbers. 2. The sum of protons and neutrons (mass number). 3. By their mass numbers (different neutron counts).
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predict the products: li + mgcl₂ → limg + cl₂ limgcl licl + mg no react…
\(LiCl + Mg\) (the orange - colored option)
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what type of reaction is fe + cl₂ → fecl₃? single replacement synthesis…
Synthesis
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the products of a combustion reaction are usually carbon and water unkn…
carbon dioxide and water
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what are the products of this reaction? cu + agno₃ -> cuno₃ + ag cu(no₃…
\(Cu(NO_3)_2+Ag\) (the second option \(Cu(NO_3)_2 + Ag\))
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___na + ___o₂ → ___nacl
2, 1, 2
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11. in addition to atomic symbol, we can represent atoms by name and ma…
a) | Symbol | Name | | ---- | ---- | | \(^{12}_{6}C^{+1}\) | Carbon - 12 | | \(^{18}_{9}F\) | Fluorine - 18 | | \(^{11}_{5}B\) | Boron - 11 | b) - **Similarities**: Both show the …
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what type of reaction is c3h8 + o2 → co2 + h2o?
Combustion
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what type of reaction is c₂h₂ + o₂ → co₂ + h₂o? decomposition synthesis…
Combustion
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is the following equation balanced or unbalanced? al + o₂ → al₂o₃
Unbalanced