化学
化学反应、化学计量、分子结构与元素性质。
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ashanti has strong feelings about the administrations policies regardin…
B. attitude
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the diagrams below show two pure samples of gas in identical closed, ri…
sample A
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terza rima means : a word repeated at the end of two consecutive lines …
a verse form with 3 - line stanzas having an interlaced rhyme scheme
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which best describes the structure of the poem \safari day in kenya\? f…
free verse with varied line lengths
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quiz question index to prepare a 100ppm chlorine sanitizing solution: p…
D. None of the above
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read this poem. feet pound pavement as miles pass, steady as tides, the…
The poem has an \(abcb\) rhyme scheme, Each stanza is a quatrain, The poem contains two stanzas.
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read the poem. instruments poised, chins high not a blink, nor a sigh a…
B. abab
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question 4: for which of the following equations is δh = δhf° for no₂(g…
D. $\frac{1}{2}\ce{N2}(g)+\ce{O2}(g)\to\ce{NO2}(g)$
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question 1: use the following reactions (i - iii) to calculate the stan…
C. - 24 kJ
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question 8 1 pts what is the easiest way to determine whether a molecul…
A. Add up the dipole moments for a 3 - dimensional structure. If the dipole moments sum to zero the structure is non - polar. If the dipole moments do not sum to zero, the structu…
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question 7 1 pts when all dipole vectors are added and cancel out, the …
non - polar.
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question 6 which of the following incorrectly assigns a dipole moment t…
$H^{\delta -}-Cl^{\delta +}$ (the first option) is incorrect in assigning the dipole moment.
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question 6 1 pts which of the following incorrectly assigns a dipole mo…
\(\ce{^{\delta +}Br - Br^{\delta -}}\)
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question 5 1 pts which of these elements has the greatest attraction fo…
Br
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question 2 1 pts what is the correct order of increasing electronegativ…
C < N < O # Question 3
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question 1 1 pts what type of bond would make a salt? covalent bond hyd…
Ionic Bond
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multiple - choice question 2al + n₂ ---> 2ain this reaction is ____. sy…
synthesis
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multiple - choice question lif + beo ---> bef₂ + li₂o this reaction is …
traded partners
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multiple - choice question 2k + mgo ---> mg + k2o in this reaction, mag…
K, potassium
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multiple - choice question 2k + mgo ---> mg + k₂o this is a ______ reac…
single replacement
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multiple - choice question 2h₂o --> o₂ + 2h₂ this is a __________ react…
decomposition
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multiple - choice question single replacement is also sometimes called …
single displacement
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multiple - choice question in a single replacement reaction, on substan…
one substance kicks another out of a compound and takes its place making a new compound
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multiple - choice question the \waste\ products of combustion is/are __…
carbon dioxide and water
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multiple - choice question combustion is when a fuel containing carbon …
oxygen
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types of chemical reactions the total number of oxygen atoms in the rea…
4
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multiple - choice question the chemical formula 2h₂o₂ represents what s…
Hydrogen peroxide
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which trait makes phospholipids useful to food manufacturers? o a. cris…
d. Emulsification
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multiple - choice question decomposition is the opposite of synthesis. …
B. true
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multiple - choice question the decomposition reaction is when a substan…
breaks down into two or more different substances
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pregunta 1 which example shows electrical energy being transformed into…
a small toaster oven toasts a bagel # Pregunta 2
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types of chemical reactions ryan oconnor types of chemical reactions co…
AB on the right side
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synthesis reaction (or combination reaction) is when two or more substa…
TRUE
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a virus has a mass of ( 9.0\times10^{-12}) mg and an oil tanker has a m…
The mass of 1 mole of viruses is \(5.4\times 10^{9}\space g\) and the number of moles of viruses with a mass equal to that of the oil - tanker is \(0.56\space mol\)
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if a scientist wants to predict when a comet or asteroid will collide w…
Gravitational attraction between all bodies.
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in the united states, how are toxic chemicals typically released into r…
accidental spills
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calculate the number of iron atoms in a 70.0 g sample of iron(iii) oxid…
\(5.29\times 10^{23}\)
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5. a solid mass of 25g is mixed with 60g of a solution. a chemical reac…
\(10\ \text{g}\)
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4. in a chemical reaction, 64g of zinc is reacted with excess oxygen to…
\(16g\)
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3. when 2.4g of magnesium reacts with 5.6g of oxygen, 8g of magnesium o…
The law of conservation of mass.
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2. a teacher places a cup of coffee onto an electronic balance at the f…
The mass displayed on the balance increases.
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practice problems 1. the conservation of mass also applies to physical …
20g
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1. 2kclo₃ → 2kcl + 3o₂ how many grams of potassium chloride are produce…
\(15.2\space g\) ### Problem 2
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one definition of energy is the ability to do work. which option below …
- Pregunta 1: The ability to cause change. - Pregunta 2: Chemical (potential) energy.
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part a a fictional element has two isotopes and an atomic mass of 87.08…
$86$ amu
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isotopes are: atoms of the same element that have different number of e…
atoms of the same element that have different number of neutrons.
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what is the symbol for the ion that forms when oxygen gains two electro…
\(O^{2 -}\)
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part a what is an ion? an ion is an atom or group of atoms that becomes…
An ion is an atom or group of atoms that becomes electrically charged due the gain/loss of electrons.
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this is the chemical formula for zinc bromate: zn(bro₃)₂. calculate the…
\(30\%\)
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which statements are consistent with rutherfords nuclear theory as it w…
- The volume of an atom is mostly empty space. - Atomic nuclei are small compared to atoms.
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what is the final temperature of 25.0 grams of water at 22.0°c after it…
24.5 °C
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part a how many kilojoules are there in 95.0 calories? 22.7 2.27 × 10⁷ …
397
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what is the law of conservation of mass? matter can be destroyed in a c…
Matter is neither created nor destroyed in a chemical reaction.
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an oxygen atom has a mass of ( 2.66\times10^{-23} ) g and a glass of wa…
The mass of 1 mole of oxygen atoms is \(16.0\text{ g}\). The number of moles of oxygen atoms with a mass equal to the mass of the glass of water is \(3.1\text{ mol}\).
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part a what is the difference between a homogeneous - mixture and a het…
A heterogeneous mixture has two or more distinct regions that have different compositions. A homogeneous mixture has only one region and the composition of the mixture does not ch…
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select the correct answer. organika pharmachemicals have designed a rar…
C. patent
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define matter. matter is defined as anything that occupies space and ha…
Matter is defined as anything that occupies space and has mass.
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for each question below, use the given information about the element to…
- Lithium: \(3\) - Chlorine: \(18\) - Magnesium: \(12\) - Boron: \(6\) - Oxygen: \(8\)
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what is the mass of 531 ml of a liquid that has a density of 0.800 g/ml…
425 g
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determine the molar mass of freon - 11 gas if a sample weighing 0.597 g…
192
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define chemistry chemistry is the science that studies the molecular tr…
Chemistry is the science that seeks to understand what matter does by studying what atoms and molecules do.
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multiple choice question a positive or negative number that indicates h…
an oxidation
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a fictional element named nivad ium is found to have three naturally oc…
22.83 amu
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1 multiple choice 2 points what is the organization of chemical element…
B. Periodic table
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2 multiple choice 2 points how are elements arranged in the periodic ta…
- **Question 2**: Increasing atomic number - **Question 3**: protons in its nucleus - **Question 4**: 118
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multiple choice question a bond in which electrons are shared unequally…
polar bond
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a molecule that does not have oppositely charged ends is called a o bal…
nonpolar molecule
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multiple select question select all that apply which factors affect the…
charge of nucleus, size of atom, number of electrons in atom
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multiple select question select all that apply which factors affect the…
charge of nucleus, size of atom
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fill in the blank question to write a chemical formula, you need to kno…
elements; ratio
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what is the name for the following molecule? n3o4= question 4 what is t…
\(N_3O_4\): trinitrogen tetroxide \(SO_2\): sulfur dioxide \(P_2Cl_5\): diphosphorus pentachloride
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multiple choice question a covalent bond in which electrons are shared …
nonpolar bond
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question 1 what is the name for the following molecule? hf= question 2 …
Question 1: hydrofluoric acid Question 2: sulfuric acid
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fill in the blank question a molecule in which the unequal sharing of e…
polar
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fill in the blank question a(n) bond is a bond in which electrons are s…
polar covalent; negative
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a molecule that does not have oppositely charged ends is called a molec…
non - polar
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fill in the blank question the symbol δ+ indicates a charge, while the …
partial positive, partial negative
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fill in the blank question the symbol δ+ indicates a charge, while the …
partial positive, partial negative
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true or false question true or false: all other factors being similar, …
False
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fill in the blank question a covalent bond in which electrons are share…
non - polar covalent
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multiple choice question a molecule in which the unequal sharing of ele…
polar molecule
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multiple select question select all that apply which correctly describe…
C. found in a molecule of nitrogen, \(N_2\) D. consists of three shared pairs of electrons E. consists of six shared electrons
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multiple choice question a bond in which electrons are shared unequally…
polar bond
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fill in the blank question a double covalent bond consists of two coval…
A double covalent bond consists of two single covalent bonds, for a total of 4 shared electrons.
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fill in the blank question a covalent bond is composed of two shared el…
single
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fill in the blank question the neutral particle that forms as a result …
molecule
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multiple choice question a covalent bond in which electrons are shared …
nonpolar bond
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multiple choice question the attraction that forms between atoms when t…
covalent
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fill in the blank question a triple bond is a bond that contains pairs …
three; six
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select all that apply which statements about the particles formed by io…
- When atoms bond covalently, they form molecules. - Molecules have a neutral charge. - Ionic compounds have a neutral charge. - Ionic compounds are made up of particles called io…
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multiple choice question a double covalent bond is composed of two sing…
4
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multiple choice question which pair of elements are likely to form ioni…
two elements located on opposite sides of the periodic table
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multiple choice question a single covalent bond is composed of _______ …
2
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fill in the blank question when the ionic compound magnesium chloride f…
two; one; ions
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multiple choice question the neutral particle that forms as a result of…
molecule
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fill in the blank question the force of attraction between the charges …
Opposite; ionic bond
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fill in the blank question the attraction that forms between atoms when…
covalent bond
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true or false question true or false: even though ionic compounds are m…
True
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fill in the blank question ionic bonding occurs between charged particl…
ions; molecules
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multiple choice question when potassium lodine forms, each potassium at…
loses one electron, forming \(K^{+}\)