Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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in what type of reaction or process does heat flow into the system? com…
D. endothermic
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two different gases are stored in separate closed containers. if both g…
D. The gas molecules in both containers have the same average kinetic energy.
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which event is endothermic? the burning of a match the change of water …
D. the melting of ice
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which answer defines exothermic reaction? a process in which energy is …
a process in which energy is released as heat
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a hot metal plate at 150°c has been placed in air at room temperature. …
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
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which reaction is exothermic? ch₄ + 2o₂ → co₂ + 2h₂o + 891 kj nh₄no₃ + …
CH₄ + 2O₂ → CO₂ + 2H₂O + 891 kJ
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name: alan martinez period: 9/25/15 the epic periodic table scavenger h…
1. Silver (Ag) 2. Zinc (Zn) 3. 57 4. Barium (Ba) 5. Lithium (Li) 6. Cobalt has more neutrons. 7. # of protons: 49; # of electrons: 52 8. Oganesson (Og) 9. Carbon and Boron - 12 (e…
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3 select the correct answer. when a candle burns, which forms of energy…
C. light and heat
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what type of property is density? both neither extensive intensive comp…
Intensive
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28. a waste management facility processes tons of garbage each day, bur…
Matter is never created or destroyed
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what is the definition of intensive property? properties that do not ch…
Properties that do not change with amount of matter
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read the following passage and find the two errors. then, choose the an…
pH is a measure of the concentration of $H^+$ ions in a solution of an acid or base. The pH plots the concentration of solutions in a range from 0 - 14.
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which question cannot be answered using scientific methods? what is the…
Which is the most interesting acid?
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a scientist dissolved a white powder in water and noted that the result…
C. Some acids do not contain hydrogen ions.
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why are intensive properties used to characterize matter? they are more…
They do not change with the amount of matter
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a student tested a sample of carbon (c) by combining it with water. the…
B. No. Just because carbon did not react with water, does not mean it wouldn't react with a different compound.
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what does the position of lithium on the periodic table tell you about …
It is in the first column, so it tends to lose one electron.
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instructions: choose an answer and hit next. you will receive your scor…
temperature
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read this excerpt from walt whitmans poem \i hear america singing\ from…
# Breve explicación: El poema tiene una estructura que imita la forma natural en que se habla, con una fluidez conversacional. No sigue un esquema de rima tradicional, no es una n…
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a student tests two solutions with the same acid - base indicator. if t…
The indicator will have different colors in the different solutions.
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which best describes the bond that would form between lithium (li) and …
They form an ionic bond by exchanging one electron.
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which of these represents three molecules of carbon dioxide? 3co₂ 3c₃o₂…
A. $3CO_2$
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which statement correctly compares barium nitrate (ba(no₃)₂) and scandi…
They contain the same number of elements.
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how many electrons does nitrogen (n) need to gain to have a stable oute…
3 (corresponding to option C if the options are numbered as in the image)
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which of the following statements best describes how a nonpolar covalen…
When the bonding atoms equally share electrons
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a certain indicator has a color chart that shows that when the indicato…
The solution has more hydronium ions than hydroxide ions.
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how could a student determine whether an unknown chemical is an acid? t…
Test the hydrogen ion concentration in the sample.
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why is water considered a polar molecule? the molecule has no overall c…
The atoms in the molecule have partial charges.
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which statement best describes the rhyme schemes of \the author to her …
Both poets use couplets for rhyme scheme and structure, inverting sentences when needed to maintain the rhyme.
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mary and ron are discussing the properties of water. mary says that whe…
Mary is correct because when water freezes, it becomes less dense than liquid water. Ice floats on liquid water, so lakes and ponds freeze at the top first.
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mary and ron are discussing the properties of water. mary says that whe…
Mary, because ice floats on liquid water indicating it is less dense.
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how many total atoms are in one molecule of lithium nitrate, lino3?
C. 5
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vii. posttest 1. chlorine has an atomic number of 17. how many electron…
1. b. seven 2. c. minus one 3. c. goes down 4. d. share 5. a. True 6. c. peptide bond 7. a. nucleotide 8. b. sugar-phosphate-sugar-phosphate, etc. 9. b. H—C—C=C—C—H (with the stru…
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read the excerpt from the author to her book. \thou ill - formd offspri…
C. A, A, B, B
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vi. organic chemistry quiz matching a. amino acid (or more than one) b.…
1. b 2. a 3. c 4. a 5. f 6. gene, enzyme, glycogen, protein, quick energy, plant cell wall 7. nucleic acid, carbohydrates, protein, fat, cellulose 8. protein, lipid, polysaccharid…
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which could be true about an unknown sample with a ph of 7? it contains…
It contains only water.
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1. why could bohrs model be called a planetary model of the atom? 2. ho…
1. Because electrons orbit the nucleus like planets orbit the sun. 2. They differ in energy levels and distances from the nucleus. 3. 32 electrons. 4. It must absorb energy to jum…
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lab data weight of sodium chloride (g) 5.77 weight of sodium chloride (…
0.00577
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what causes matter to change to a different phase? a change in energy a…
a change in energy
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which study did classical roman scholars make important contributions t…
D. geography
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the step in a reaction mechanism is the slowest step and determines the…
rate - determining; rate
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are substances that increase reaction rates by providing an alternative…
Catalysts; activation energy
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graph 4: exposure to chemical releases according to race racial biases …
Fewer chemicals are released in areas where white people live.
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5. which molecule has a central carbon atom with four different compone…
5. Amino - acid 6. a) Amino group ($-NH_2$) b) Carboxyl group ($-COOH$) c) Hydrogen atom ($-H$) 7. Nucleotide 8. Contain C, H, O; are organic molecules 9. General example: $C_6H_{…
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why must total mass logically stay the same in a chemical reaction acco…
If the number of atoms stays the same during a reaction no matter how those atoms are rearranged, their total mass must also stay the same.
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what is different about the law of conservation of matter compared to \…
law of conservation of mass deals with grams instead of atoms
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question 8 10 pts the law of conservation of mass and matter can both b…
A. balanced
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in a chemical reaction, what has to be the same on both sides of the re…
the number of atoms and types of elements
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what is a simple (\in short\) way to summarize the law of conservation …
matter is neither created nor destroyed, only transformed
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how is the total amount of matter impacted when materials react with ea…
in every case, the total amount of matter afterward is the same as before
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describe how to identify a subscript in a chemical formula and its impa…
it is the small number to the lower right of the element symbol and shows how many atoms of an element are present
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describe how to identify a coefficient in a chemical formula and its im…
it is before the element symbol and shows how many complete particles of a substance are needed
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how does the battery create electricity? a) magnetism. b) electrical po…
C. Chemical reaction
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question 2 10 pts how can you tell when a new element symbol is startin…
look for the capital letter
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question 2 how can you tell when a new element symbol is starting in a …
look for the capital letter
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what does a chemical formula show you? the elements involved in a chemi…
the elements involved in a chemical reaction using the symbols of the elements that make up the substances
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which symbol represents the element with the greatest average atomic ma…
# Explicación: ## Paso 1: Conocer las masas atómicas promedio La masa atómica promedio de Fe (hierro) es aproximadamente 55.85 u. La masa atómica promedio de Ag (plata) es aproxim…
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what do we call atoms with differing numbers of neutrons? nuclei; ons; …
# Breve explicación: Los isótopos son átomos del mismo elemento químico que tienen el mismo número de protones pero diferente número de neutrones en su núcleo. # Respuesta: D. Iso…
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if an atom has more or less electrons than protons, what is it called? …
# Breve explicación: Un átomo neutro tiene la misma cantidad de electrones que protones. Cuando un átomo tiene más o menos electrones que protones, adquiere una carga eléctrica y …
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17 elección múltiple 1 punto what is the name of the element with 82 pr…
# Explicación breve: El número atómico de un elemento es igual al número de protones en su núcleo. El número atómico del plomo (Lead) es 82. # Respuesta: D. Lead
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using the periodic table, and the atomic mass for helium, find how many…
2
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how many protons are in an atom of the element oxygen? (use a periodic …
# Explicación: ## Paso 1: Buscar en la tabla periódica El número atómico de oxígeno es 8. ## Paso 2: Relación con protones El número atómico es igual al número de protones en un á…
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which subatomic particle has mass, a positive charge, and denotes the i…
# Breve explicación: Los electrones tienen carga negativa. El núcleo no es una partícula subatómica individual sino una región del átomo. Los neutrones son neutros eléctricamente.…
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atoms are comprised of three subatomic particles. which set describes t…
# Breve explicación: Los átomos están compuestos por protones, neutrones y electrones. Los protones tienen carga positiva y se encuentran en el núcleo, los neutrones no tienen car…
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periodic trends worksheet using the periodic table and your knowledge o…
1a. Bi 1b. As 1c. O 1d. Po 1e. F 1f. Cs 2. Metal 3. Distance from nucleus to outermost electron shell 4. Across a period: decreases; Down a group: increases 5. Cs (or Fr in genera…
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1. solubility in water 2. describe how salt dissolves in water chemical…
Salt dissolves in water chemically through dissociation, where water molecules surround and separate the ions in the salt. # 4.
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carbon dioxide gas escaping a soft - drink can in the form of bubbles i…
C. pressure
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____ has little effect on the solubility of solids and liquids but does…
D. Pressure
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____ aids dissolution because it disperses - or spreads out - the solut…
Stirring or agitation
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____ affects dissolution because dissolution takes place on the surface…
C. Size of the solid
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according to the graph, what can you conclude about the effect of tempe…
Solubility increases as temperature increases
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the process of dissolving a substance is ____ disturbance supersaturati…
C. dissolution
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8) choose the correct term that completes each sentence. olivia added s…
1. Unsaturated 2. Saturated 3. Supersaturated
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what are the three states of saturation? transaturated supersaturated s…
B. supersaturated, D. saturated, F. unsaturated
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sugar particles left over that cannot be dissolved in a solution ____. …
D. are crystals
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a(n) ____ is a solution with less than the maximum amount of solute. dy…
D. unsaturated solution
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____ is the ability of a solution to include more dissolved solute than…
B. Supersaturation
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the ____ is the limit at which a solvent cannot dissolve any more solut…
D. saturation point
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a solution in which the rates of crystallization and dissolution are th…
C. dynamic equilibrium
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what determines how much, if any, of a solute is dissolved? application…
C. saturation
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potential energy was transferred into each of the following objects to …
stone - potential energy of slingshot arrow - potential energy of bowstring baseball - stored energy in human arm cannonball - chemical potential energy of gunpowder
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use the graph on the right to answer the following questions. a. estima…
c. 35000 feet; There is no altitude at which the pressure is exactly zero because there will always be some air molecules present in the atmosphere, resulting in a non - zero (alb…
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question 5 (1 point) wood chips are what type of food safety hazard? ch…
B. Physical
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the factor - label method can be used to solve virtually any problem in…
1. 0.035 L 2. 0.95 kg 3. 27.5 cm 4. 1 kL 5. 1 L 6. 4.5 g 7. 250 mm 8. 0.5 dag 9. 7.5 cm 10. 15000 mg
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question 4 (1 point) false ownership is a violation of the rules and gu…
TRUE ### Question 5
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chem 203 - tutorial 1: stoichiometry and gas properties part 1 - group …
No specific final answer due to incomplete problem statement. General steps for solving are provided above.
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ch₂o how many atoms of carbon were in the reactants of this equation gi…
1
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solve the following problems. write the answers in significant figures.…
1. 10800 2. 0.0035 3. 12.1 4. 90 5. 11388 6. $1.806\times 10^{24}$ 7. 4.15 8. 112 9. 4.46 10. $1.34\times10^{24}$ 11. 186 12. 7.5
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which choice provides the best summary of the passage? the maillard rea…
The Maillard reaction is a chemical reaction that occurs between acids and sugars, causing foods to brown and gain a rich flavor. This process enhances the smell and taste of cert…
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alculate the density of the following objects. object\tmass (g)\tvolume…
Oxygen density: 0.0014 g/mL Water density: 1 g/mL
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drag and drop each description to classify is as a characteristic of me…
Metals: Have the highest melting and boiling points, Are very ductile Metalloids: Intermittent properties Nonmetals: Have the lowest melting and boiling points, Includes most gases
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listed in the item bank are key terms and expressions, each of which is…
Metals: Good conductor, High luster, Left side of PT Metalloids: An element with intermediate properties Nonmetals: Right side of PT, Noble Gas
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how do soils form? o plants cement mineral particles together to form s…
Weathering breaks rocks into minerals, and plants die and decay.
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how does the inorganic portion of soil form? soils get formed by meltin…
Rocks get weathered by chemical and physical means to form soils.
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part 1: use the notation below to answer the following questions. 12c 1…
| Hyphen Notation | Nuclear Notation | Atomic # | Mass # | # of $p^{+}$ | # of $n^{0}$ | # of $e^{-}$ | |---|---|---|---|---|---|---| | Uranium - 235 | $^{235}U$ | 92 | 235 | 92 |…
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which element has the smallest ionization energy, na, f, i, cs? cs beca…
Cs because, as an alkali metal with a large size, there is a weak electrostatic attraction between the protons and the valence electrons.
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what is the overall trend for the electron affinity of atoms across the…
Electron affinity decreases down the groups and increases from left to right across the periods.
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moving left to right across the periodic table, electronegativity _____…
C. increases; decreases
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why do we use metals in wires? (select all that apply.) metals are reac…
Metals conduct electricity., Metals are ductile.
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which family has a full valence shell, making them the least reactive g…
noble gases