Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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when a ca metal atom loses both of its valence electrons it attains an …
Question 1: the noble gas Ar Question 2: selenium
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question 19 as the electronegativity difference increases between two n…
Question 19: D. ionic Question 20: A. polyatomic ions
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question 17 1 pts when two covalently bonded atoms have the same or sim…
Question 17: evenly, nonpolar Question 18: unevenly, polar
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electrons in a polar covalent bond are shifted toward the least electro…
False D. increases, decreases
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question 13 1 pts in the case of a polar covalent bond, the atom with a…
Question 13: B. partial positive charge Question 14: B. Electronegativity
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a _______________ is formed when bonding electrons are attracted to one…
First question: D. polar covalent bond Second question: C. partial negative charge
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when two nonmetal atoms such as chlorine share electrons to form a cova…
1. B. eight 2. B. False
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a chemical bond is simply the internuclear distance at which the______ …
1. D. lowest potential energy 2. A. True
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the distance between two atoms at which the lowest potential energy is …
- First question: B. bond length - Second question: C. electrons
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molecular compounds that contain covalent bonds exhibit different prope…
For the first question: lower melting points, may be liquids or gases, generally softer. For the second question: False
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ionic bonding results from the electrostatic attraction of_ oppositely …
1. A. oppositely charged ions 2. C. sharing
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when main group metals form cations, they tend to lose all of the _____…
1. B. valence 2. B. the outer s and p orbitals
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ionic compounds do not exist as discreet units of a single pair of ions…
Question 1: B. three - dimensional lattice structure Question 2: B. strong electrostatic attraction
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the formula of an ionic compound is given as the__________the number of…
1. C. simplest ratio of 2. B. False
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a is made up of two elements where one is a metal and the other a nonme…
1. D. binary ionic compound 2. True
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the properties of ions are very different from the neutral atoms from w…
1. True 2. C. sodium chloride (table salt)
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ionic bonds are the consequence of electrostatic forces between atoms w…
Question 1: C. oppositely charged cations and anions Question 6: - rigid and brittle - high melting and boiling points - a crystalline structure - dissolve readily in water
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when a neutral atom gains one or more electrons from its valence shell …
1. B. an anion 2. D. salts
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question 1 1 pts ions are atoms or molecules bearing an odd number of n…
Question 1: an positive or negative charge Question 2: valence shell
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isotopes of the same element are different from one another in that mul…
They have a different number of neutrons.
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you can painlessly wade into a pool, but doing a belly flop off of the …
water's higher density compared to the air.
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given the data in exercise 115, calculate the energy that must be remov…
\(-151.25\ kJ\)
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given the data in exercise 115, calculate the energy that must be remov…
If the molar - mass of \(X\) is known, substitute into \(Q=\frac{250}{M}\times75.0\ kJ\) to get the energy value. For example, if \(M = 50\ g/mol\), the answer is \(375\ kJ\)
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which element is present in all amino acids, but not necessarily in fat…
C. nitrogen
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which atoms are in all carbohydrates? carbon, hydrogen, oxygen carbon, …
carbon, hydrogen, oxygen
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which phrase names a direct result of hydrogen bonding? the polar ends …
cohesion and adhesion
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which property of water is likely the most significant in water’s role …
Water molecules have positive and negative sides.
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atoms of which three elements could bond together to form an organic co…
D. carbon, hydrogen, and oxygen
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the dots in each diagram represent valence electrons orbiting the nucle…
(Assuming the diagram with 4 dots is one of the options, without seeing the actual dot - counts in each diagram we can't precisely pick the letter, but the correct answer is the d…
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why is carbon present in so many types of molecules? it can become an i…
It can form up to four covalent bonds.
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how are hydrogen bonds different from covalent bonds? o they have valen…
Hydrogen bonds are weaker bonds that form from molecules that have a slight positive charge on one side and a slight negative charge on the other.
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why can a carbon atom can form a variety of compounds? o it has 2 valen…
It has 4 valence electrons that allows it to bond with up to 4 other atoms.
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how is an organic compound different from an inorganic compound? inorga…
Organic compounds contain carbon atoms bonded to other atoms.
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according to the concept of entropy, what will likely happen to most mo…
They will break down.
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which type of bond holds atoms together in a water molecule? nuclear bo…
D. covalent bond
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what element do all organic compounds have? oxygen phosphorus nitrogen …
D. carbon
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what is the most important role of hydrogen bonding between water molec…
It enables water molecules to bond to each other.
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which statement is true about water molecules? water molecules move ran…
The oxygen atom has a slight negative charge.
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william bradford 1621 a certain indian came boldly amongst them and spo…
C. saw examples of divine providence in everyday life.
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william bradford, 1621. a certain indian came boldly amongst them and s…
B. Native Americans formed complex communities capable of developing alliances for their own self - interest.
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which statement describes carbons unique bonding ability? carbon can ea…
Carbon can easily form 4 covalent bonds with other atoms.
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which molecules are considered organic? o those containing phosphorus o…
those containing carbon
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william bradford 1621 a certain indian came boldly amongst them and spo…
A. The interaction between English colonial settlers and Native Americans in the early 17th century.
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question 35 2.5 points save answer read the following scenario and answ…
eutrophication
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if energy cannot be destroyed, why do some people worry about the energ…
The concern is with usable sources of energy.
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identify the element and determine the valence electrons. | electron co…
| Electron Configuration | Element Symbol | Valence Electrons | | ---- | ---- | ---- | | $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}5s^{1}$ | Rb | 1 | | $1s^{2}2s^{2}2p^{6}…
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13.kr 5s² 4d¹⁰5p³ explain what is wrong with the following electron con…
13. Incorrect sub - shell filling order. 14. 4d filled before 5s contrary to Aufbau principle. 15. 3s sub - shell has more than maximum 2 electrons.
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9. radium 10.iodine determine what elements are denoted by the followin…
11. Element: S 12. Element: Rb 13. Element: Sb 14. Error: Incorrect orbital - filling order, should fill $3d$ before $4d$. 15. Error: $3s$ sub - shell cannot have 3 electrons. For…
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electronic configuration practice- use periodic table with electron con…
1. $1s^{2}2s^{2}2p^{6}3s^{1}$ 2. $1s^{2}2s^{2}2p^{6}3s^{2}$ 3. $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{6}$ 4. $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}$ 5. $1s^{2}2s^{2}2p^{6}3s^{2}3…
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name ______________ period ______________ history of atomic theory fill…
| Name of Researcher | Equipment/Experiment | Sketch of Model | Major Idea/Discovery | | ---- | ---- | ---- | ---- | | Dalton | N/A | N/A | All atoms of a given element are identi…
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fill in the missing information in the chart below: name of researcher …
| Name of Researcher | Equipment/Experiment | Sketch of Model | Major Idea/Discovery | | ---- | ---- | ---- | ---- | | Dalton | N/A | N/A | All atoms of a given element are identi…
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the rate of a chemical reaction varies, depending on the initial amount…
7
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choose the correct electron configuration for chlorine (cl). 1s² 2s² 2p…
1s² 2s² 2p⁶ 3s² 3p⁵
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the last 6 columns on the periodic table corresponds to which sublevel …
A. the p sublevel
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compute the average atomic mass for silicon: isotope percent abundance …
28.09
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which of the following could have 82 neutrons? w-182 cs-132 ba-138 ta-1…
Ba - 138
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choose the correct electron configuration for beryllium (be). 1s² 2s² 2…
1s² 2s²
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which energy change takes place when gasoline evaporates from a fuel ga…
Energy is absorbed.
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atom 1 has mass=12 protons=6 atom 2 has mass= 14 electrons=6 are these …
C. Isotopes of Carbon
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the molar heat of fusion of gold is 12.550 kj mol⁻¹. at its melting poi…
$3,688.3\ g$
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an ice cube is dropped into a glass of milk at 20°c. which statement ex…
Because milk has higher KE than ice, KE is transferred from the milk to the molecules of ice.
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the overall change in enthalpy of a reaction depends only on the reacta…
the reactants and the products.
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which statement describes mechanical energy? the energy that is associa…
the sum of the kinetic energy and the potential energy of an object
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which statement describes mechanical energy? the energy that is associa…
the sum of the kinetic energy and the potential energy of an object
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* if two or more atoms of the same element dont satisfy the octet rule,…
Yes.
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proposed lewis structure is the proposed lewis structure reasonable? ye…
1. No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are: C 2. Yes. 3. Yes.
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arrange the highlighted bonds in the table below in decreasing order of…
C - F: 1, C - C: 3, C - O: 2
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question 12 the element with the electron configuration 1s²2s²2p⁶ is a …
C. Ne
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date identifying chemical bonds identify each of the following as a com…
1. Elements: Hydrogen, Oxygen; Bond: Covalent 2. Elements: Carbon, Hydrogen; Bond: Covalent 3. Elements: Hydrogen, Chlorine; Bond: Covalent 4. Elements: Phosphorus, Oxygen; Bond: …
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question 11 at most, how many electrons can occupy the second shell? a …
C. 8
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the study of gas behavior helped establish early chemistry as a legitim…
TRUE
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test content page 10 of 25 question 10 which of the following can be cl…
B. baking soda (sodium bicarbonate)
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the primary goal of the earliest chemists was to gain an understanding …
# Breve explicación: Los primeros químicos se dedicaban a estudiar los materiales y los cambios que estos experimentaban con el objetivo de comprender cómo funcionaba el mundo. # …
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question 8 which of the following best describes saltwater (nacl in h2o…
B. Saltwater is a mixture whose particles can be physically separated.
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test content page 7 of 25 question 7 calcium is an example of a(an) ___…
B. alkaline earth
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question 8 which element is most likely to have chemical properties sim…
C. Be (atomic number 4)
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what subatomic particle explains the periodicity of elements? neutrons …
# Breve explicación: La periodicidad de los elementos en la tabla periódica se debe a la estructura electrónica de los átomos. Los electrones se organizan en capas y sub - capas, …
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page 4 of 25 question 4 the symbol of the element with 46 protons is a …
D. Pd
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name & #: devin b. 3 name the following compounds: 1) n₂o₅ 2) sebr₆ 3) …
1. Dinitrogen pentoxide 2. Selenium hexabromide 3. Methane 4. Benzene 5. Phosphorus hexafluoride 6. Boron trifluoride 7. Diphosphorus tetraiodide 8. Disulfur trichloride 9. Nitrog…
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question 2 in a neutral atom, the number of protons must equal the numb…
B. False
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name the following compounds: 1) n₂o₅ 2) sebr₅ 3) ch₄ 4) c₆h₆ 5) pf₅ 6)…
# Explanation: ## Step1: Name $N_2O_5$ It is a covalent compound. The prefix for 2 is "di -" and for 5 is "penta -". The first element is nitrogen and the second is oxygen (ending…
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which statement among a - c is false regarding the redox reactions show…
None of the above statements are false.
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test content page 1 of 25 question 1 xenon is an example of a(an) _____…
B. noble gas
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what type of ion do alkali metals form? negative ion/anion molecule pos…
positivo ion/cation
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what type of metals are found on the leftmost side of the periodic tabl…
# Breve explicación: Los metales alcalinos se encuentran en el lado más izquierdo de la tabla periódica. Son los elementos del grupo 1 (excepto el hidrógeno). Los halógenos son no…
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how many elements did characteristics repeat every in the early list of…
eight elements
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which statement among a - c is false regarding the redox reactions show…
None are false; all are true statements.
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which statement among a - c is false regarding the redox reactions show…
None are false; all are true statements.
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how many elements were in the periods for the first two rows of mendele…
B. ten
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what characteristic of elements did mendeleev realize was more importan…
# Breve explicación: Mendeleev descubrió que la reactividad química era un factor crucial para ordenar los elementos en la tabla periódica, y fue más importante que el peso atómic…
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multiple - choice question what element is not found in carbohydrates? …
B. Nitrogen
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an individual was exposed to a contagious disease but did not become in…
B. physical barrier
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chapter 4 - chemistry conversions test review show your work! make sure…
1. 249680 inches 2. 15144 hours 3. 764.785625 miles/h 4. 91.25 cases/year
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select the correct answer. a molecule of carbon moves through various m…
B. air
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select the correct answer. how does the carbon locked in shells of mari…
A. through subduction of deposits and volcanism
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astronomers can determine the chemical composition of stars by observin…
Wavelengths of light emitted by the star.
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update 2024 on singapores green plan 2030 https://www.youtube.com/watch…
a. 53.465 million tonnes b. 47.175 million tonnes
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question 7 which one of these spills can be cleaned up by laboratory pe…
Small spills (less than 100 mls) that are contained to the biosafety cabinet or fumehood work surface
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6 combien y a - t - il de moles d’eau (h₂o) dans 1 l d’eau (1 000 g d’e…
$55.56\ mol$
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5. use the data in the table to calculate the density of each unknown s…
| Mass (g) | Volume (cm³) | Density (g/cm³) | Substance | | ---- | ---- | ---- | ---- | | 171 | 15 | 11.4 | | | 108 | 40 | 2.7 | | | 475 | 250 | 1.9 | | | 680 | 1000 | 0.68 | |