化学
化学反応、化学量論、分子構造、元素の性質。
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multiple - choice question what is the next step? ✓ add the relative ab…
Multiply the mass of each isotope by its relative abundance.
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the % of the parent isotope remaining after 2 half lives.
\(25\%\)
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which of these is a property of a substance that is composed of atoms t…
It can be flattened and bent.
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multiple - choice question which is true about the average atomic mass …
It's closest to the mass of the most abundant isotope.
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which statement explains why the bonds between nonmetals tend to be cov…
They have small differences in electronegativity.
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which statement describes the valence electrons in ionic bonds? they ar…
They are transferred from one atom to another.
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which interaction is responsible for the force of attraction between th…
proton - electron
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question 12 of 15 the 1995 nobel prize in chemistry was shared by paul …
$-19.85$
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types of chemical bonds which statement is generally true about cacl₂? …
Its bonds are formed by large differences in electronegativity.
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calculate the standard enthalpy change for the reaction at 25°c. standa…
\(-2043.9\)
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which type of substances have chemical bonds that are not directional a…
metals
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what is the most likely mass of a randomly selected boron atom? 6, beca…
11, because boron - 11 is most abundant
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what will most likely happen when two bromine atoms bond together? a me…
C. A covalent bond will hold them together.
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sugar is made up of clear, colorless crystals that dissolve easily in w…
It is made up of atoms that are held together by covalent bonds.
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select the correct answer. how does regular exercise help make us more …
C. During exercise the brain releases endorphins, the chemicals that help improve our mood
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the incomplete table shows selected properties of compounds that have i…
covalent bond and low melting point
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which statement describes how the bond between two oxygen atoms is form…
by sharing valence electrons between the two atoms
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atmosphere structure troposphere and stratosphere what is one of the ch…
high density of air molecules
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comparing bonds in metals and nonmetals which type of bond involves two…
covalent
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which of the following chemical substances has a triple covalent bond? …
Carbon monoxide (CO)
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comparing bonds in metals and nonmetals which type of bond has elements…
ionic
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completing a chart on the characteristics of bonds identify the placeme…
A. No B. Yes (en estado líquido o disueltos) C. Yes D. No E. Yes
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7 in restaurants, red heat lamps are put above food to keep it warm. th…
7. b. radiation 8. c. The heat from the hot water is conducted through the spoon.
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insert two dashes where needed. at sunfest organic farm a cutting - edg…
At Sunfest Organic Farm — a cutting - edge herb farm in Okeechobee, Florida — the herbs are washed with ultraviolet light in a vacuum - sealed room.
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which statement best compares the melting points of magnesium and sodiu…
Magnesium has a higher melting point because it contributes two additional electron per atom than sodium in the electron sea.
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the image shows the unit cell for perovskite (catio4). it was discovere…
The melting point of perovskite is \(1980^{\circ}C\) because the electrostatic attraction between atoms holds them close together.
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explain the digestive system, including the structures involved and the…
The digestive system's structures (mouth, esophagus, stomach, small intestine, large intestine, rectum/anus) work together to break down food (mechanical and chemical digestion), …
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multiple choice 1 point which statement explains whether nacl or beo wi…
BeO will have a stronger bond because it has a larger ionic charge, and a smaller distance between ions.
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multiple choice 1 point 1 an atom x has three electrons in its outermos…
\(X^{3+}\)
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how many atoms of lithium (li) are present in the compound given the su…
C. 36
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a student has a compound of cateo₃ the student wants there to be a tota…
Place a coefficient of 5 before the Ca.
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how many total atoms are present in this compound? 4 zn₂sio₄ 7 24 13 28
28
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answer the following questions to show your understanding of how subscr…
it makes 8 copies of the complete molecule
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how many atoms of hydrogen would there be total with a coefficient of 3…
\(6\)
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what subscript is missing from this compound if the student calculated …
\(6\)
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how many elements are present in this compound? 5 ch₃ona 6 15 4 30
C. 4
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question 2 what does the 6 in the following formula tell you? c₂h₆o₄ th…
there are 6 atoms of hydrogen
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the small number that tells how many atoms of an element are present tw…
- For "The small number that tells how many atoms of an element are present": Subscript - For "Large number to the left of a compound that tells you how many of the complete compo…
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b) identifier les changements de phase
- Gaz → Solide : Dépôt - Gaz → Liquide : Condensation - Liquide → Solide : Solidification
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potassium nitrate, kno₃, has a molar mass of 101.1 g/mol. in a constant…
\(q_{soln}=2.31\ kJ\) \(\Delta H_{rxn}=7.39\ kJ/mol\)
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match the following vocabulary terms to the correct descriptions that w…
1. Chemical formula 2. Element symbol
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question 4 of 15 consider the reaction diagram. this reaction is endoth…
$\Delta H = 25\ kJ/mol$
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during an experiment, a student adds 1.81 g cao to 300.0 ml of 1.000 m …
\(-194\space kJ/mol\)
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12-identifie les changements de phase... a)
- Solide → Gaz : sublimation - Liquide → Gaz : évaporation (ou vaporisation) - Solide → Liquide : fusion
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question 14 of 17 the specific heat of a certain type of cooking oil is…
\(8475\) cal
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graded quiz: nutrition and digestion 0:00:46 elapsed what action in the…
A. Mechanical digestion
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julian works as a freelance photographer specializing in portrait and e…
billing, making appointments, and customer service
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question 12 of 17 the table provides molar heat capacities (c_m) of sel…
$0.444\ J/(g\cdot K)$
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consider an ideal gas enclosed in a 1.00 l container at an internal pre…
\(-2837.1\ J\)
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question 7 of 17 a sample of gas occupies a volume of 59.2 ml. as it ex…
\(1320\space mL\)
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if the wrong word is used below, change it. if there is no error, click…
Elias Begay offered to advise the chemists on how to mix the formula, but they wouldn't listen to him.
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25 chlorine has an electronegativity of 3.16. fluorine has an electrone…
Fluorine is more reactive with water. Because fluorine has a higher electronegativity than chlorine. Fluorine has a stronger tendency to gain electrons. The reaction of fluorine w…
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correct to solve the problem, begin with 30.95 inhg, convert the pressu…
\(104.8\ kPa\)
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which website citations are formatted correctly? select three options. …
B. Greene, Tom. Home Composting. Hanover Growers Guild, 15 March 2010. Web. 22 April 2011. D. Lee, Kim. Stake Your Tomatoes. Future Farmers of America, n.d. Web. 24 June 2012. E. …
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5 multiple choice 2 points given the diagram representing a reaction: w…
fission
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what is the electron configuration for the following element: nitrogen …
1s²2s²2p³
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a scientist is conducting an investigation that involves water, silver,…
They are each made of matter. Some are compounds and some are elements. They all contain atoms.
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what is the electron configuration for the following element: silican n…
\[ [Ne]3s^{2}3p^{2} \]
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what is the electron configuration for the following element: helium 1s…
\(1s^{2}\)
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what is the electron configuration for the following element: fluorine …
Ninguna de las opciones dadas es correcta para el flúor (\( Z = 9 \), configuración \( 1s^{2}2s^{2}2p^{5} \) o \( [He]2s^{2}2p^{5} \)). Pero si se asume un error tipográfico y se …
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what is the electron configuration for the following element: lithium 1…
# Explicación breve: El número atómico del litio es 3. Esto significa que tiene 3 electrones. Los electrones se distribuyen en orbitales según las reglas de construcción (Aufbau p…
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what is the electron configuration for the following element: magnesium…
# Explicación breve: El número atómico del magnesio es 12. La configuración electrónica de Ne (neón) es \(1s^{2}2s^{2}2p^{6}\). Después de Ne, los electrones se agregan en el nive…
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your friend asks you to explain how you know that a particular work is …
Cubism uses geometric shapes and multiple perspectives.
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elección múltiple 1 punto what is the electron configuration for the fo…
\( 1s^{2}2s^{2} \)
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question 14 · 1 point why is a carbonyl group polar? select the correct…
Carbon is significantly less electronegative than oxygen.
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question 13·1 point why is a carbonyl group polar? select the correct a…
B. Oxygen is significantly more electronegative than carbon.
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question 12 · 1 point which of the following best describes the term al…
An aldehyde contains a carbonyl group that is attached to one hydrogen atom and usually one carbon substituent.
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3 elección múltiple 1 punto what is the electron configuration for the …
[Ne]3s¹
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question 11 · 1 point why is a carbonyl group polar? select the correct…
Oxygen is significantly more electronegative than carbon.
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question 10 · 1 point identify the name of the straight - chain alcohol…
1,2-pentanediol
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what is the electron configuration for the following element: oxygen 1s…
# Explicación breve: El número atómico del oxígeno es 8. Esto significa que tiene 8 electrones. La configuración electrónica se construye llenando los orbitales en orden de energí…
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1 elección múltiple 1 punto what is the electron configuration for the …
\(1s^{2}2s^{2}2p^{6}3s^{2}\) (la primera opción)
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question 8 · 1 point which among the following is not true for phenols?…
C. They are more basic than aliphatic alcohols.
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question 7 · 1 point the unhybridized p orbital of the carbon in a carb…
C. π
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question 6 · 1 point what is the geometry of a carbonyl group? select t…
trigonal planar
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10 elección múltiple 1 punto what element has the following ground - st…
neon
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question 5: 1 point what type of bonds are formed within the hybridized…
A. Sigma
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question 4 - 1 point the melting point of phenol is 40.5^{circ}c and th…
A. The (-OH) group on phenol can form hydrogen bonds, and the -CH₃ group on toluene cannot.
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9 elección múltiple 1 punto what element has the following ground - sta…
# Explicación breve: Para determinar el elemento, contamos el número total de electrones. En el diagrama orbital de estado fundamental, hay 2 electrones en \(1s\), 2 en \(2s\) y 1…
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question 3 · 1 point which of the following alcohols is a liquid at roo…
D. all of the above
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23a identify and label which atom represents fluorine (f) and which ato…
The atom on the left is Fluorine. The atom on the right is Chlorine.
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8 elección múltiple 1 punto what element has the following ground - sta…
boron
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question 2 · 1 point what is the name of a secondary alcohol with the f…
C. 2-propanol
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7 elección múltiple 1 punto what element has the following ground - sta…
# Explicación breve: Para determinar el elemento, contamos el número total de electrones. En el diagrama orbital de estado fundamental, el 1s tiene 2 electrones, el 2s tiene 2 ele…
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most alcohols are not arrhenius bases. bases like naoh and koh have oh⁻…
C. $-\text{OH}$
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6 elección múltiple 1 punto what element has the following ground - sta…
# Explicación breve: Para determinar el elemento, contamos el número total de electrones. En el diagrama orbital, los subniveles 1s, 2s y 2p se llenan. - 1s tiene 2 electrones ($1…
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23a identify and label which atom represents fluorine (f) and which ato…
The atom on the left is Fluorine. The atom on the right is Chlorine.
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panyin wants to use this research for her expository essay. because org…
Research shows that organic foods pose less danger to human health than nonorganic foods.
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question ch₃ch₂ch₂c(o)ch₃ is called select the correct answer below: he…
pentanone.
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5 elección múltiple 1 punto what element has the following ground - sta…
helium
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which statement best describes the relationship between activation ener…
Natural Science: Chemistry B. Reducing the activation energy can increase the rate of a reaction.
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4 elección múltiple 1 punto what element has the following ground - sta…
# Explicación breve: Para determinar el elemento, se cuenta el número de electrones en el diagrama de orbitales de estado fundamental. En este caso, hay un solo electrón en el orb…
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question which of the following molecules is not an aldehyde? select al…
A. \((\text{CH}_3)_3\text{COH}\), C. \(\text{CH}_3\text{COCH}_3\)
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question the term carbonyl group best fits which of the following descr…
C. A carbonyl group is a carbon atom double - bonded to an oxygen atom.
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question 5 of 10 read this passage: wendy is trying to learn more about…
A. Comparing different stories on the same topic
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3 elección múltiple 1 punto what element has the following ground - sta…
# Explicación breve: Para determinar el elemento, contamos los electrones en el diagrama de orbitales. En el diagrama, hay 2 electrones (1 en 1s y 1 en 2s). El número atómico (núm…
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question ch₃ch₂ch₂ch₂ch₂cho is called select the correct answer below: …
heptanal.
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2 elección múltiple 1 punto what element has the following ground - sta…
# Explicación breve: Para determinar el elemento, contamos los electrones en el diagrama de orbitales. En el diagrama, hay 2 electrones en el orbital 1s, 2 en el 2s y 2 en el 2p. …
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which of the following is the formula for the simplest aldehyde? select…
\(\text{HCHO}\)
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1 elección múltiple 1 punto what element has the following ground - sta…
hydrogen