化学
化学反应、化学计量、分子结构与元素性质。
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balance the following reaction. type your answer... naf + type your ans…
2, 1, 2, 1
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step 3: apply the scaling factor to the empirical formula. the scale fa…
\(10\)
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why did the federal government create this program in 1933? a to establ…
9. D. To provide jobs and improve the regional standard of living 10. B. Prolonged drought and poor farming practices
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step 3: apply the scaling factor to the empirical formula. the scale fa…
\(5\)
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1 multiple choice 2 points balance the following equation. ___alcl₃→___…
\(2AlCl_3 ightarrow2Al + 3Cl_2\) (the fourth option)
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step 2: determine the scaling factor. what is the scaling factor if the…
\(5\)
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calculate the molecular formula for a compound with a molar mass of 150…
\(30.03\ \text{g/mol}\)
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calculate the molecular formula for a compound with a molar mass of 150…
\(30.03\) g/mol
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which is not a requirement for matter to be classified as a mineral? so…
organic
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3 multiple choice 2 points balance this reaction: \\_\\_\\_k+\\_\\_\\_c…
\(2K + 1Cl_2 ightarrow2KCl\) (the first option)
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water (h₂o) is composed of two hydrogen atoms and one oxygen atom. ther…
compound
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6 multiple answer 1 point s₈ + 8o₂ -> 8so₂ which of the following are r…
C. \(O_{2}\), D. \(S_{8}\)
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the equation for the ph of a substance is ph = -logh+, where h+ is the …
\([H^+]=10^{-7.2}\) (the second option)
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the equation for the ph of a substance is ph = -logh+, where h+ is the …
\([H^{+}]=10^{-7}\) (the second option)
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h₂o draw the molecule by placing atoms on the grid and connecting them …
The Lewis structure of \(H_2O\) has an oxygen atom in the center. It is bonded to two hydrogen atoms (\(H - O - H\)). There are two lone pairs of electrons on the oxygen atom.
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cations have a _ charge. a positive b negative c frivoluscharg
A. Positive
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two different isotopes of zinc a) b) c) d). a have different chemical p…
B. have the same chemical properties
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carbon - 12 and carbon - 13 a both have the same number of protons b bo…
A. Both have the same number of protons
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muslim american scientific innovators technological pioneers american m…
femtochemistry
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muslim american scientific innovators technological pioneers american m…
the Nobel Prize
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elements in the same period a have the same properties. b have similar …
C. Have the non - metals on the right side
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elements in the same group a have the same properties b have similar pr…
B. have similar properties
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on the periodic table metals are found on the ___ and nonmetals are fou…
A. left side, right side
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metals tend to _____ electrons and nonmetals tend to _____ electrons a …
C. lose, gain
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the nucleus of an atom does not contain a subatomic particles b protons…
and Solution according to the required format
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the atomic number indicates a the number of neutrons in a nucleus b the…
C. the number of protons in a neutral atom
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what was rutherfords (gold foil experiment) most important discovery? a…
D. Atoms have a very small positively charged nucleolus (assuming it's a typo for nucleus)
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which labels apply to acetone? choose all answers that apply: molecule …
A. molecule, C. compound, D. chemical
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which labels apply to diamond? choose all answers that apply: molecule …
D. chemical
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which labels apply to potassium iodide? choose all answers that apply: …
B. salt, C. compound, D. chemical
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7. the combustion of the organic fuel, decane, is outlined in the chemi…
a. \(50\space mol\) b. \(11.625\space mol\) c. \(\approx5.64\space mol\)
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is the energy of a star related to its lifespan? a stars mass dictates …
A. Stars mass dictates the temperature and pressure present within the core,, which determines the lifespan
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a common chemical reaction involves two ionic compounds that exchange i…
- Reactants: \(K_2SO_4 + Ba(NO_3)_2\) (first option for reactants) - Products: \(BaSO_4+KNO_3\) (second option for products)
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you might need an periodic table which of these elements forms ions wit…
D. cesium
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4. équilibre les équations chimiques suivantes. (6 points) a) __al(s) +…
a) \(4Al_{(s)}+3O_{2(g)}\to 2Al_{2}O_{3(s)}\) b) \(CH_{4(g)}+4Cl_{2(g)}\to CCl_{4(g)} + 4HCl_{(g)}\) c) \(2FeCl_{3(l)}\to 2Fe_{(s)}+3Cl_{2(g)}\)
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what element has the electron configuration 1s²2s²2p⁶3s²3p²? nitrogen s…
First Question: silicon Second Question: decreases as you move from left to right across a period.
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what element in the second period has the largest atomic radius? carbon…
- First question: lithium - Second question: principal energy level
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group 1 metals can bond with group 16 nonmetals to form ionic compounds…
\(2\)
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nf₃ draw the molecule by placing atoms on the grid and connecting them …
The Lewis structure of \(NF_3\) has a central nitrogen atom bonded to three fluorine atoms. Each \(N - F\) bond is a single bond. Nitrogen has one lone pair of electrons and each …
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which of the following factors contributes to the increase in atomic si…
- First question: more shielding of the electrons in the highest occupied energy level. - Second question: Electronegativity generally increases from left to right across a period.
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asbestos is composed of magnesium ions (mg²⁺), silicate ions (si₂o₅²⁻),…
\(Mg^{2 +}\) and \(Si_{2}O_{5}^{2-}\): Ionic bond \(Si\) and \(O\): Covalent bond \(Si_{2}O_{5}^{2-}\) and \(OH^{-}\): Ionic bond \(O\) and \(H\): Covalent bond \(Mg^{2+}\) and \(…
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categorization 3 points classify the following as metals or nonmetals. …
Metals: Barium, Potassium, Calcium Nonmetals: Iodine, Nitrogen, Phosphorus
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in class, a science teacher demonstrates what happens when vinegar and …
D. The balloon fills with a gas produced when the vinegar and baking soda are mixed.
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multiple answer 1 point which of the following form anions? check all t…
Fluorine, Sulfur
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5. un échantillon contient 2,36g de mg(oh)₂. (8 points) a) quelle est l…
a) \(58,33\ g/mol\) b) \(0,04046\ mol\) c) \(2,437\times10^{22}\) molécules d) \(1,2185\times10^{23}\) atomes
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the illustration shows two kinds of matter: which best explains how piz…
B. Pizza is a suspension, and milk is a solution.
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5. un échantillon contient 2,36g de mg(oh)₂. (8 points) a) quelle est l…
a) \(58,33\ g/mol\) b) \(0,0405\ mol\) c) \(2,44\times10^{22}\) d) \(1,22\times10^{23}\)
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during a class activity, students used colored candles to create models…
B. The candles in the dish representing elements are all one color and the candles in the dish representing the heterogeneous mixture are four different colors, so elements have o…
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multiple choice 1 point which of the following will form an ionic compo…
Sodium and chlorine.
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10 multiple choice 1 point which of the following will form a covalent …
Hydrogen and oxygen.
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exercise 13.5 equilibrium & ice tables name: date: per: the equilibrium…
1. \(K_c = [Ca^{2+}][SO_4^{2 -}]\) 6. \(K_c=\frac{[NOCl]^2}{[NO]^2[Cl_2]}\)
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nomenclature & formulas quiz version a name: period: 1. the elements in…
1. b. - 2 2. d. + 2 3. b. 1 4. a. + 1 5. d. hexa 6. c. MgO 7. b. \(Ba_{3}N_{2}\) 8. b. \(SnSe_{2}\)
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during a class activity, students used colored candles to create models…
B. The candles in the dish representing elements are all one color and the candles in the dish representing the heterogeneous mixture are four different colors, so elements have o…
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which of the following form anions? check all that apply. sodium sulfur…
Sulfur, Fluorine.
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sasha is conducting an experiment with water, salt, and eggs to see if …
B. density; The salt causes the water to be denser which causes the egg to float.
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multiple answer 1 point 1 which of the following form cations? check al…
Calcium, Aluminum
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38. a certain reaction has the following general form: aa→bb at a parti…
a. Rate law: \(Rate = k[A]\), Integrated rate law: \(\ln[A]=\ln[A]_0 - kt\), Rate constant \(k = 2.97\times10^{-2}\text{ min}^{-1}\) b. \(t_{1/2}\approx23.3\text{ min}\) c. \(t\ap…
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chimie 311 evaluation formative module 2 nom: / 30 points = 1. a) dans …
a) \(6,80\times 10^{23}\) molécules de \(Na_{2}O\) b) \(1,36\times 10^{24}\) atomes de Na 2) \(1,28\ mol\) d'eau
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2. when dissolving a solid in water, the test tube feels warm. is the r…
The reaction is exothermic.
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ellie was comparing samples of substances to determine if they were a p…
B. She is incorrect because Sample B contains different types of substances and should be classified as a pure substance.
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your science teacher lit a wax candle, asked students to carefully obse…
D. The mass of the wick, the wax that burned, and the oxygen that helped the flame before the reaction equals the mass of the smoke and the gases released after the reaction.
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a group of students conducted an investigation in which they observed c…
A. the paper can be burned
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the molecules on the left represent ch₄ and o₂. combustion of methane d…
A. Yes, because atoms are the same in the reactants and products.
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penny placed a tablet of baking soda in a cup of water. the tablet imme…
B. chemical; the fizzing sound indicates a new substance was formed
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mrs. smith asked her class to classify several products as pure substan…
A. Distilled white vinegar should be moved into the group of pure substances.
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which best compares compounds and mixtures? oa compounds and mixtures c…
C. Mixtures can be made up of elements and compounds that lack definite proportions, but a compound is composed of elements that are present in definite proportions.
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4) choose all that apply. choose two facts about hydrologists. most hyd…
- They collect and analyze water samples, set up monitoring equipment, and use computers to model the behavior of water systems. - They study how evaporation and water cycles affe…
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in class, a science teacher demonstrates what happens when vinegar and …
D. The balloon fills with a gas produced when the vinegar and baking soda are mixed.
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therefore, the name for the ionic compound mg₃p₂ is magnesium phosphide…
B. strontium fluoride
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propane (c₃h₈) is a fossil fuel. its stored in pressure tanks so it can…
The second option (the one with all single bonds between carbon atoms) is the correct Lewis structure for propane.
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7. the combustion of the organic fuel, decane, is outlined in the chemi…
a. \(50\space mol\) b. \(11.625\space mol\) c. \(\approx5.64\space mol\)
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not all energy sources derive their energy from the sun. choose the thr…
nuclear, geothermal, tidal
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lithium fluoride (lif) and nitrogen trifluoride (nf₃) are both fluorine…
B. \(NF_3\)
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which groups on the periodic table are likely to lose valence electrons?
Groups 1 and 2.
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complete the statement. the number of covalent bonds a nonmetal forms c…
group
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eugenol is present in the oil extracted from clove, a spice used to fla…
B. double bond
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which groups of elements are never found as pure elements in nature? in…
Alkali metals (Group 1) and halogens (Group 17 or 7A).
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use the following equation to solve the problems below: 3 sio₂ + 4 al →…
i. \(8.0\space mol\) ii. \(6.0\space mol\) iii. \(4.0\space mol\)
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strontium sulfate (srso₄) is composed of strontium and sulfate (so₄²⁻) …
A. ionic
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open-ended question why are the halogens the most reactive non - metals…
Halogens are the most reactive non - metals because they have 7 valence electrons and a high electronegativity, readily gaining one electron to achieve a stable electron configura…
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mg + cuso₄ → cu + mgso₄ synthesis decomposition single displacement dou…
Single Displacement
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bacl₂ + na₂so₄ → baso₄ + 2nacl synthesis decomposition single displacem…
Double Displacement
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al + cl₂ → alcl₃ synthesis decomposition single displacement double dis…
Synthesis
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fe + o₂ → feo synthesis decomposition single displacement double displa…
Synthesis
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open-ended question list 3 properties of the transition metals. type yo…
1. High melting and boiling points. 2. Variable oxidation states. 3. Good catalytic properties.
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match the following vocabulary words. match the items in the left colum…
1. potential energy 2. chemical energy 3. displacement 4. work 5. electrical energy 6. tidal energy 7. force 8. geothermal energy 9. acceleration due to gravity 10. heat energy 11…
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ca(oh)₂ + h₂so₄ → caso₄ + 2h₂o synthesis decomposition single displacem…
Double Displacement
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h₂o₂→h₂o+o₂ synthesis decomposition single displacement double displace…
B. Decomposition
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agno₃ + nacl → agcl + nano₃ synthesis decomposition single displacement…
Double Displacement
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cao + h₂o → ca(oh)₂ synthesis decomposition single displacement double …
Synthesis
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kbr + cl₂ → kcl + br₂ synthesis decomposition single displacement doubl…
C. Single Displacement
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group 18 is also known as the.... a alkali ne earth metals b transition…
D. noble gases
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co + o₂ → co₂ synthesis decomposition single displacement double displa…
Combustion
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c₆h₁₂o₆ + 6o₂ → 6co₂ + 6h₂o synthesis decomposition single displacement…
Combustion
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hgo→ hg + o₂ synthesis decomposition single displacement double displac…
B. Decomposition
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zn + h₂so₄ → znso₄ + h₂ synthesis decomposition single displacement dou…
Single Displacement
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anwar al - sadat and menachem begin won the nobel peace prize in 1978 f…
signing the Camp David Accords.
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ch₄ + o₂ → co₂ + h₂o synthesis decomposition single displacement double…
Combustion
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5 multiple choice 1 point how should chemicals be stored? in food stora…
away from prep areas
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2h₂o → 2h₂ + o₂ synthesis decomposition single displacement double disp…
B. Decomposition