化学
化学反応、化学量論、分子構造、元素の性質。
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which best describes why absolute zero is the lowest possible temperatu…
B. At absolute zero, the motion of the molecules of a substance almost stops.
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a bowl of hot soup that is left on the counter will eventually cool dow…
B. the heat from the soup moving into the cooler air.
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orbital diagrams and electron configurations 1 chem complete these in y…
The solutions involve drawing orbital diagrams and writing electron configurations as analyzed above for each species (P, \(P^{3-}\), K, \(K^{2+}\), Br, \(Br^-\), Fe, \(Fe^{2+}\),…
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as a solid goes through a phase change to liquid, heat is absorbed and …
A. Remains the same.
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based on their locations on the periodic table, which set of elements h…
O lithium (Li), sodium (Na), potassium (K)
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question 40 (1 point) from the table given below, which base is the str…
C. \( \text{C}_2\text{H}_5\text{NH}_2 \), Ethylamine
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question 39 (1 point) the table below shows the solubility product cons…
E. \( \text{Pb(OH)}_2 \), Lead hydroxide
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consider the density data in the table at right. the sample is thought …
0.28 g/cm³
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which is not a conjugate acid-base pair? $\\ce{h3o+}$ and $\\ce{h2o}$ $…
$\ce{NH3}$ and $\ce{NH2^{2-}}$ (the option with $\ce{NH3}$ and $\ce{NH2^{2-}}$)
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the average density for a substance was determined as 6.5 g/ml. the sam…
about 12%
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question 38 (1 point) which is not a conjugate acid-base pair? \\(\\ce{…
The option with $\ce{HNO2}$ and $\ce{H2O}$ (the last option: $\boldsymbol{\ce{HNO2}}$ and $\boldsymbol{\ce{H2O}}$)
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question 37 (1 point) which of these is present in all acid-base system…
D. a and b (where a is hydronium ions and b is hydroxide ions)
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question 36 (1 point) if additional acid is added to an acid-base syste…
A. concentration of hydronium ions increase and concentration of hydroxide ions decrease
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question 33 (1 point) use the following information to answer the next …
\(6.3\times 10^{-7}\space\text{mol/L}\) (the option with \(6.3\times 10^{-7}\space\text{mol/L}\))
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which statement best describes why absolute zero is the lowest possible…
B. It is the temperature at which particles have minimum possible energy and motion cannot decrease further.
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question 32 (1 point) three bottles are labelled as shown: | bottle 1 |…
Bottle 3 > Bottle 1 > Bottle 2
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question 31 (1 point) which of the following combinations will not resu…
Ethanoic acid - hydrochloric acid
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when iron is burned, it combines with oxygen to form iron oxide. the ta…
D. A chemical reaction occurs because the density of iron is different from the density of iron oxide
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four preparations involving table sugar (sucrose) are described below. …
A. the color change that takes place after heat melts and begins to decompose the sugar
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when olive oil and sodium hydroxide are mixed together, soap and glycer…
B. This is a chemical reaction because the materials that were mixed have different solubilities than the materials that were made.
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11 directions: select all the correct answers. hannah does an experimen…
A. A brown solid forms in the bottom of the beaker, B. The temperature of the chemicals rises 15°C, C. A yellow gas forms, D. The chemicals change color from colorless to purple
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gerald’s science teacher mixed liquid x and liquid y, both at room-temp…
D. A chemical reaction produced a new substance.
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question 30 (1 point) a student prepares a $\\ce{ch_{3}cooh-ch_{3}coona…
A. ethanoic acid - sodium acetate
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hydrogen gas (h₂) and oxygen gas (o₂) react to form liquid hydrogen per…
A. The atoms of the reactants have combined to form a new substance.
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choose all of the compounds below. □ ozone (o₃) □ water (h₂o) □ nitroge…
The compounds are: - water (\(H_2O\)) - carbon dioxide (\(CO_2\)) - sodium chloride (\(NaCl\))
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7 when substances go through chemical changes, which of the following w…
C. One or more substances with different chemical properties will form.
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pure sodium metal explodes when it makes contact with water. in its nat…
D. When substances are chemically combined, the properties of the new substances that are formed are often different from the properties of the original substances.
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iron (fe) and diatomic oxygen (o₂) combine to produce iron(iii) oxide (…
A. A chemical reaction occurred because iron(III) oxide has different properties than iron and diatomic oxygen.
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question 29 (1 point) use the following information to answer the next …
A. In reaction (i) hydrogen phosphate acts as a Brønsted acid and in reaction (ii) it acts as a Brønsted base.
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baking soda and vinegar can be used to model a volcanic eruption in a s…
D. Vinegar and baking soda react to form a new gaseous substance.
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which set of coefficients will balance this chemical equation? __c₂h₄(g…
1, 3 (corresponding to the option "1,3")
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question 28 (1 point) which of the following substances can act as a br…
$\ce{H2O(l)}$ (the option with $\ce{H2O(l)}$)
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observe the chemical equation written by an eighth grade student. cu + …
C. The number of oxygen atoms in the reactants equals the number of oxygen atoms in the products.
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b. solvent c. homogeneous mixture d. heterogeneous mixture 7. a mixture…
B. Heterogeneous mixture ### Question 8
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a. pure substance b. element c. homogeneous mixture d. heterogeneous mi…
B. Soap ### Question 3
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59. according to modern atomic theory, what is the primary difference b…
The option: "They have a different number of neutrons." (the third option in the list)
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1. (1) ... (5) ... 2. (6) the salt water and the salt crust of the sali…
The second option (the middle one) with the text: "There are high quantities of sodium - which is what we consider basic table salt - which people need to ingest in small quantiti…
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58. which type of element is most likely to donate electrons to form a …
C. A metal
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55. which of the following ideas was part of daltons atomic theory but …
C. Atoms of the same element are always identical (in mass and size).
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52. which statement accurately describes an electron? a subatomic parti…
The correct option is the third one (labeled as "A subatomic particle with a negative charge located outside the nucleus."). If we assume the options are ordered from top to botto…
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51. which of the following elements, when combined with chlorine (cl), …
B. Lithium (Li)
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50. what is the first step you should take if a chemical splashes into …
B. Alert a nearby instructor or lab partner and proceed to the eyewash station for at least 15 minutes of flushing.
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18. which mineral is commonly used in ceramics and glass? a. feldspar b…
A. Feldspar ### Question 19
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47. which of the following is a property of elements in the same group …
A. They have similar chemical properties
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when oil is the fuel at hand (kerosene), it should be kept from the sur…
The correct option is the one labeled "Endothermic process" (the second option in the list, assuming the first is "Endothermic process" – based on the context, the option with "En…
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45. magnesium chloride has the chemical formula mgcl₂ what does the sub…
There are two chloride ions for every magnesium ion.
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44. what fundamentally describes the nature of a metallic bond? the att…
The option (the top - most option, partially visible text: "The attraction between positive metal ions and a 'sea' of mobile, delocalized valence electrons")
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43. which element has the following electron configuration? 1s2 2s2 2p6…
D. Zinc (Zn)
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42. what is the correct ground state electron configuration for an atom…
B. \(1s^2 2s^2 2p^6 3s^2 3p^2\) (and C. \(1s^2 2s^2 2p^6 3s^2 3p^2\) as they are identical; assuming the second and third options are the correct ones with this configuration)
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41. which of the following best describes a covalent bond? a bond forme…
D. A bond formed by the sharing of electrons between two nonmetals. (Note: Assuming the options are labeled A, B, C, D in order. If the last option is, say, D, then this is the an…
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38. what is the charge of an ion that has gained one or more electrons?…
Negative (the option with "Negative" text)
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36. what do the periods (rows) on the periodic table represent? the num…
D. A principal energy level
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34. for an element in its ground state, which electrons are most involv…
D. The valence electrons (assuming the options are labeled A - D with D being "The valence electrons"; if original labels differ, adjust to match, e.g., if the last option is labe…
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minerals & identification quiz 1. which of the following is not a chara…
C. Made by humans ### Question 2
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chemistry semester 1 exam on level 25-26 possible points 3.41 how many …
- Triple bond: 6 electrons (3 electron pairs). - Double bond: 4 electrons (2 electron pairs). - Single bond: 2 electrons (1 electron pair).
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chemistry semester 1 exam on level 25-26 silicon-30 contains 14 protons…
A. 14
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which evidence supports the argument that amino acids can be a result o…
The correct option is: Sugar molecules contain carbon, hydrogen, and oxygen that can form amino acids.
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bacl₂ + li₂so₄ → 2licl + baso₄ the reactants are: blank and blank and t…
Reactants: $\ce{BaCl2}$ (the option with $\ce{BaCl2}$) and $\ce{Li2SO4}$ (the option with $\ce{Li2SO4}$); Products: $\ce{LiCl}$ (the option with $\ce{LiCl}$) and $\ce{BaSO4}$ (the…
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chemistry semester 1 exam on level 25-26 possible points: 1.14 which ty…
D. metallic bonds
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what is a requirement for studying food density in food processing? * s…
A. Scientific method application ### Second Question:
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chemistry semester 1 exam on lever possible points: 1.14 which type of …
D. metallic bonds (assuming the last option is labeled D; if the options are as listed with the last being "metallic bonds", the answer is the option with "metallic bonds")
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chemistry semester 1 exam on level 25-26 all of the following are corre…
Atomic Radius (the option with arrows ← and ↑)
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chemistry semester 1 exam on level 25-26 possible points: 1.14 the tota…
A. \(s = 2\), \(p = 6\), \(d=10\), \(f = 14\)
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4fe₂o₃ 4fe₂o₃ 4fe₂o₃ \yields\ or \produces\ eacts with\ used to represe…
- \( \boldsymbol{4}\text{Fe}_2\text{O}_3 \) → coefficients - \( 4\text{Fe}_{\boldsymbol{2}}\text{O}_{\boldsymbol{3}} \) → subscripts - \( 4\boldsymbol{\text{Fe}_2\text{O}_3} \) → …
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26. which of the following elements is a noble gas? helium oxygen chlor…
Helium (the option with "Helium" text)
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28. an ionic bond is formed by the electrostatic attraction between: tw…
a cation and an anion
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part c — the matter inside the bubble 7. what type of matter is the air…
Circle: Mixture
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24. the modern periodic table is arranged in order of increasing: atomi…
The option with "Atomic number" (the first option among the choices, labeled as "Atomic number" in the provided options).
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23. a reaction that releases energy into its surroundings, causing the …
B. Exothermic reaction
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chemistry semester 1 exam on level 25-26 the periods and groups on the …
A. krypton (Kr), group 18
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chemistry semester 1 exam on level 25-26 which is the correct molecular…
The second option (the one with \( O = C = O \) and proper electron dots around each \( O \))
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20. which of the following is an acceptable form of attire for a chemis…
C. Closed - toe shoes with long pants or a lab coat.
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chemistry semester 1 exam on level 25-26 isotopes are atoms of the same…
B. neutrons
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18. as you move from left to right across a period on the periodic tabl…
The option "It increases." (the second option with the corresponding radio button)
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chemistry semester 1 exam on level 25-26 a measure of the ability of an…
C. electronegativity
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which is the atomic number of an atom with six valence electrons? a 6 b…
B. 8
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which term identifies a chemical property that can be used to different…
A. reactivity
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given the pair of elements below, show a. the electron dot diagrams for…
### 1. Na and Cl a. $\text{Na} \cdot$; $\cdot \underset{\cdot \cdot}{\overset{\cdot \cdot}{\text{Cl}}} \cdot$ b. Na donates 1 electron to Cl. c. $\text{Na}^+$ and $\text{Cl}^-$ d.…
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type of reaction match the correct type of reaction to each equation: 2…
- \( 2C_4H_{10}+13O_2 ightarrow 8CO_2 + 10H_2O \): Combustion - \( Pb(NO_3)_2 + 2KI ightarrow PbI_2+2KNO_3 \): Double Replacement - \( 2NaHCO_3 ightarrow Na_2CO_3 + CO_2 + H_2O \)…
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the diagram below shows a portion of a buret. what is the reading of th…
B. 31.72 ml
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one of our tanks launch long-range rockets at enemy aircraft break the …
B. Break the stalemate
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when sugar is dissolved in water, the solution is classified as a: a he…
D. homogenous mixture
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in each stanza, the rhyme scheme is abba. in a sense, the rhyme between…
C. a feeling of conclusion in the fourth line.
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what is the correct structure for bf₃ ?
The first structure (with B bonded to three F atoms via single bonds, each F having three lone pairs of electrons).
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unit 2: cannabis notes learning target: i can explain key concepts of m…
- Marijuana acts on the **endocannabinoid** system which has **receptors** all over the brain and body... - Two main active compounds: **THC** & **CBD**. - THC is responsible for …
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which of the following is not a treatment or test used for a fracture? …
B. Chemotherapy
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which statement describes a chemical property of an element? a silver r…
A. Silver reacts with hydrogen sulfide.
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chemistry semester 1 exam on level 25-26 which of the following is the …
\( S_4N_2 \) (the last option, e.g., D. \( S_4N_2 \) if options are labeled D for the last one)
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considering the elements: sulfur, chlorine, selenium and bromine, which…
D. Chlorine
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chemistry semester 1 exam on level 25-26 a family of elements that has …
B. Group 17 (Note: Here we assume the options are labeled as A. Group 7, B. Group 17, C. Group 5, D. Group 2. If the original options have different labels, adjust accordingly. Bu…
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chemistry semester 1 exam on level 25-26 which sequence correctly place…
I. Br, Cl, F (the option "I, Br, Cl, F")
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the most reactive group of metals is group and the most reactive group …
The most reactive group of metals is group \(\boldsymbol{1}\) and the most reactive group of nonmetals is group \(\boldsymbol{17}\) (or group 7A in some numbering systems).
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according to le chatelier’s principle, what happens when the concentrat…
A. The equilibrium shifts to the right to favor the formation of products.
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litio configuración electrónica del átomo neutro diagrama orbital del á…
Configuración electrónica: \(1s^2 2s^1\) Diagrama orbital corregido: \(1s\) \(\uparrow \downarrow\), \(2s\) \(\uparrow\), \(2p\) (tres cuadrados vacíos)
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top 10 chemical reaction in our everyday lives name scott amesim direct…
| Reaction Name | Reactants | Products | |-----------------------------|------------------------------------|------------------------------------| | Combustion of Propane | $\ce{C…
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diagrama orbital del átomo neutro 1s 2s 2p
El átomo representado en el diagrama orbital es el litio (Li), ya que tiene 3 electrones (2 en 1s y 1 en 2s), correspondiente al número atómico 3.
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which statement best describes how dynamic equilibrium relates to a sat…
Each second, the amount of solid sodium chloride that dissolves equals the amount of solid sodium chloride that recrystallizes.
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question: 40 of 45 a pharmacy technician is accustomed to working with …
Use a syringe with an anti - lock fitting.
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question: 39 of 45 a pharmacy technician is putting away an order of ch…
ISO class 7
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which of the following types of therapy should be given to a patient wh…
B. Total parenteral nutrition