化学
化学反応、化学量論、分子構造、元素の性質。
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the element which is used as a standard to measure the mass of one mole…
d. Carbon
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33) a 4.0 - liter container has two gases inside, neon and argon. it is…
33) A. 0.042 moles argon 34) A. 0.245 moles
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the element which is used as the base to calculate the atomic mass of a…
A. Carbon
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the introduction of a neutron into the nuclear composition of an atom w…
FALSE
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the isotope oxygen - 18 has an atomic number of 8. which of the followi…
A. 8 protons, 8 electrons, 10 neutrons
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19) the kinetic molecular theory describes the behavior of ____________…
19) Particles 20) True 21) D. All of the above 22) True
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the chemical properties of a given element are dictated by: a the numbe…
A. the number of protons and the number of electrons
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16) there are a variety of acids and bases. scientists would call anyth…
16. D. Strong acid 17. B. Strong base 18. False
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when two or more atoms differ only in the number of neutrons that each …
B. mass only
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13) salts are ____________ compounds formed during the reactions betwee…
13) Ionic 14) False 15) A. pH is less than seven, B. sour taste, D. turns litmus indicator from blue to red
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11) identify all the examples of a base according to the table below. h…
B. Sodium Hydroxide, D. Ammonia
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complete each of the following metacommentary templates in any way that…
a. All businesses will thrive as a result b. explore the broader implications of chemical regulation on public health
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4) an unknown substance is added to a solution and the ph increases. th…
4) B. base 5) C. 7
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1) ____ are chemical substances that are slippery to touch. 2) ____ are…
1. Bases 2. Acids 3. B. decrease
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22) a chemist is studying the following reaction: no + no₂ -> n₂o₃. she…
22) A. The reaction will continue until all the NO or all the $NO_2$ is used up. 23) True 24) True
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21) what do the comparison of q = 6.2 and k = 1.2 indicate? 1.2 6.2 k q…
A. The reaction must shift to the left.
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19) which of the following statements is true about the equilibrium in …
19. C. Equilibrium is reached when the amount of water moving back and forth is equal. 20. D. The rates of the forward and reverse reactions are equal; E. The concentrations of th…
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17) if q > k: a) the concentrations of reactants and products are stabi…
17) C. Q is larger than K. 18) A. The reaction must shift to the right, producing more products.
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how do we determine if a reaction is at e q = products/reactants 15) wh…
15) The reaction quotient, which is the ratio of the concentrations (or partial pressures for gas - phase reactions) of products to reactants at a given moment in the reaction. 16…
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7) which two of the following characteristics are a reversible reaction…
7. B. reaction that can occur in not only the forward direction, but also the reverse direction, C. double - sided arrow 8. True 9. D. closed
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5) when we consider the general form of a chemical equation, what is th…
5) C. It indicates that the reaction occurs only in one direction; A. It implies that all of the reactants are converted into the products 6) A. A single - sided arrow; D. reactio…
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2) when differentiating between chemical and physical properties of mat…
2. Substance 3. Reactant 4. Product
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question 9 the atmosphere on early earth (4.5 to 3.8 billion years ago)…
allowed the chemical processes that led to early life
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question 3 mark this question which of the following is the best exampl…
Purchasing only organic vegetables after learning about the damaging effects of pesticides
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there are two common isotopes of the element lithium. the first isotope…
C. lithium - 6 and lithium - 7
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there are ______ neutrons in the stable isotope of rhenium (re - 185). …
A. 110
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you will need to obtain a periodic table. tin is an example of an eleme…
d. 70
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2. which color scheme did the artist use in their artwork?
# Breve explicación: El diagrama muestra tonos, sombras y matices de los colores, lo que sugiere un enfoque en los conceptos básicos de la paleta de colores en arte. Los términos …
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how many neutrons does the isotope of hydrogen called deuterium (₂¹h) h…
B. one
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this exam is closed - book. before starting, make sure you have studied…
A. trigger - point massage
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3. what volume does a 1 - carat (0.2 g) diamond occupy? diamonds densit…
0.06 mL
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one gallon (3785 ml) of gasoline has a mass of 2540 g. what is the dens…
0.671 g/mL
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15. which type of reaction is illustrated by the equation 2h₂o → 2h₂ + …
B. Decomposition
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14. in the combustion of methane $ch_{4}+2o_{2}\to co_{2}+2h_{2}o$, how…
C. 4
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10. which of the following represents a violation of the law of conserv…
C. A chemical reaction in which the total mass of products is less than the total mass of reactants
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8. when sodium chloride reacts with silver nitrate, what are the produc…
D. Sodium nitrate and silver chloride
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6. which type of reaction is the opposite of a synthesis reaction? a. d…
A. Decomposition
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which is an example of a chemical change that could be reversed by anot…
# Breve explicación: Los cambios físicos no alteran la identidad química de una sustancia, mientras que los cambios químicos sí la alteran. La oxidación (mancha) en una moneda de …
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dissolving salt in water is an example of chemical change. true false
# Breve explicación: La disolución de sal en agua es un cambio físico, no químico. No se forma un nuevo compuesto químico; simplemente la sal se disocia en iones en el agua y se p…
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a physical change occurs when food spoils. true false
# Explicaciones breves: La spoilage de alimentos es un cambio químico. Esto se debe a que las reacciones químicas, como la oxidación y la descomposición por acción de microorganis…
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what may be released as a sign that a chemical change has occurred? a a…
# Breve explicación: En una reacción química, la evolución de burbujas suele ser una señal de que se está liberando un gas, lo cual es un indicador de que ha ocurrido un cambio qu…
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which of these is a chemical change? a painting a fence b an apple rott…
# Explicación breve: Un cambio químico implica una reacción química que produce una sustancia nueva con propiedades diferentes. Pintar una valla es solo una aplicación física de l…
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how many oxygen atoms (o) are in a carbon dioxide molecule? hint: in th…
2
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in its pure form, what state of matter is carbon? solid plasma liquid
solid
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which of these describes a chemical change? a breaking glass b burning …
# Breve explicación: Un cambio químico implica la formación de una sustancia nueva con propiedades químicas diferentes. Cuando se quema el papel, se produce una reacción química y…
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iron benches placed in lawns and gardens become. this is a change becau…
Oxidados, cambio químico
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how many total atoms are in a carbon monoxide molecule? hint: the spher…
2
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how many oxygen atoms (o) are in a carbon monoxide molecule? hint: in t…
B. 1
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filling in the gaps use the table to find the songs parts. detail types…
| Stanza | Repetition | Alliteration | Rhyme Scheme | | ---- | ---- | ---- | ---- | | "Last night, I was so high, I almost jumped out of the window. Last night, I was so high," | …
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water at room temperature is in what state of matter? gas solid liquid
C. Liquid
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iron benches placed in lawns and gardens become. this is a change becau…
# Explicación breve: La oxidación del hierro en presencia de oxígeno y agua forma óxido de hierro (moho), lo que es una reacción química que produce una nueva sustancia. # Respues…
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which of these is a chemical change? a baking a cake b dissolving salt …
# Explicación breve: La cocción de un pastel implica reacciones químicas entre los ingredientes (por ejemplo, el bicarbonato de sodio reacciona con ácidos en la masa para producir…
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which of the following correctly describes a chemical property? a chemi…
A. A chemical property involves a chemical change.
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which of the following are types of chemical change? select all that ap…
# Breve explicación: La opción a es un cambio físico (fusión), mientras que las opciones b, c y d implican cambios en la composición química de las sustancias. En b, dos elementos…
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chemical changes include ______. a elements combining with other elemen…
# Breve explicación: Los cambios químicos implican la formación de nuevos compuestos. La combinación de elementos, la descomposición de compuestos y la reacción de compuestos para…
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which of the following correctly describes why metals and nonmetals ten…
Metals tend to lose their valence electrons while nonmetals gain electrons.
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which of these is a chemical change? a melting of ice b inflating a bal…
# Explicación breve: La fusión del hielo es un cambio de estado físico (sólido a líquido), inflar un globo es un cambio físico en la forma y volumen del globo, y el picado de made…
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question select all the correct answers. which two possible explanation…
C. White light contains seven colors, which are separated by the prism.
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which of the following best evaluates the chemical reactivity of the st…
The chemical would be reactive because it has fewer than 8 valence electrons.
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which of the following best describes why noble gases do not form compo…
Their full valence shell makes them unreactive.
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how many valence electrons does the element nitrogen have?
5
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which element would be a better conductor of electricity? o nickel, bec…
Nickel, because it is a metal and metals donate their electrons.
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how many neutrons are in a calcium (ca) atom? atomic mass: 40.078 atomi…
20
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how many neutrons are in a silver (ag) atom? atomic mass = 107.868 atom…
61
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which of these is the atomic symbol of carbon? 12.011 6 c
C
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how many neutrons are in a cobalt (co) atom? atomic mass: 58.933 atomic…
32
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which of the following best describes the atomic structure of bromine? …
35 protons and an average of 45 neutrons in the nucleus, and 35 electrons outside the nucleus
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question 19 4 pts what is true about an electron? charge choose mass ch…
charge: -1 mass: virtually zero location: outside the nucleus role in an atom: responsible for reactivity
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quiz instructions this exam is closed - book. before starting, make sur…
Anaphylaxis
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according to the chemthink tutorial; what is true about a proton? charg…
charge: +1 mass: heavy location: in the nucleus role in the atom: determines the identity of the atom
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during a lab, a student places a metal in a solution. she notices bubbl…
If a new substance with new properties is forming, she is observing a chemical change. If the metal is just evaporating and no new substance is formed, she is observing a physical…
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question 15 why do we call atoms neutral?
Atoms are called neutral because the number of protons (positive charges) is equal to the number of electrons (negative charges), resulting in a net charge of zero.
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question 14 where are these atomic particles located? proton choose neu…
Proton: inside the nucleus Neutron: inside the nucleus Electron: outside the nucleus
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small quantities of oxygen can be prepared in the laboratory by heating…
$11.04\ g$
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a classmate is stating that there is enough energy in a system to have …
The reactants are not colliding at the correct orientation.
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when heated, kclo₃ decomposes into kcl and o₂. 2kclo₃ → 2kcl + 3o₂. if …
14.7 g
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has a chemical reaction taken place? two liquids are mixed together and…
For the first question: Yes, because a gas has started to form. For the second question: The products are not colliding at the correct orientation.
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why do collisions between atoms or molecules occur more slowly at lower…
There is less energy available.
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in a chemistry experiment, a student is analyzing data to draw conclusi…
Recognizing and addressing potential sources of error or uncertainty.
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question 12 8 pts what charge do these particles have? proton choose ne…
Proton: positively charged Neutron: neutral Electron: negatively charged
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question 1 what must take place in order for a reaction to take place? …
The collision must have the correct orientation and the correct amount of energy.
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question 11 4 pts based on what you learned from the chemthink tutorial…
C. protons and neutrons
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please answer the questions with the words and explanations that you le…
hold protons together
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how many covalent bonds is nitrogen (group 5a) likely to form? (1 point…
three
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which type of bond and how many bonds would occur as carbon dioxide (co…
four covalent bonds
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quiz instructions please answer the questions with the words and explan…
False
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question 8 8 pts what is the center of the atom called?
Nucleus
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metallic bonds are responsible for many properties of metals, such as c…
The bonds can shift because valence electrons are held loosely and move freely. Metals have low electronegativity, so they are conductive because they pass charges easily.
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please answer the questions with the words and explanations that you le…
neutrons, protons
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please answer the questions with the words and explanations that you le…
False
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if ba2+ ions bond with p3- ions, which of the following would be the ch…
Ba3P2
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which of the following bonds would be best categorized as ionic? i. h -…
C. II only
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when looking at the periodic table, the whole number of an element repr…
A. atomic number
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for the chemical reaction, 3koh + h₃po₄ → k₃po₄ + 3h₂o. what mass of ph…
69.6 g
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please answer the questions with the words and explanations that you le…
A. the atomic number
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question 3 4 pts how do you know what element you have? how many shells…
the number of protons
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water cycle review part 1: a water molecules journey. using the startin…
| Starting Location | Ending Location | Transition(s) Name(s) | What drives this/these transition(s)? | | --- | --- | --- | --- | | Clouds | River | Precipitation, Collection | Gr…
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part 1: a water molecules journey. using the starting and ending locati…
| Starting Location | Ending Location | Transition(s) Name(s) | What drives this/these transition(s)? | | ---- | ---- | ---- | ---- | | Clouds | River | Precipitation, Collection …
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how many oxygen atoms (o) are in a carbon dioxide molecule? hint: in th…
2
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in its pure form, what state of matter is oxygen? liquid solid gas
Gas