化學
化學反應、化學計量、分子結構與元素性質。
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an analytical chemist measures the amount of elements $e_1$ and $e_2$ i…
Is $X$ a pure substance or a mixture? pure substance If you said $X$ is a pure substance, calculate the mass of Element $E_1$ the analytical chemist would find in a new 10.0 g sam…
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an analytical chemist measures the amount of elements $e_1$ and $e_2$ i…
Is $X$ a pure substance or a mixture? pure substance If you said $X$ is a pure substance, calculate the mass of Element $E_1$ the analytical chemist would find in a new 10.0 g sam…
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an analytical chemist measures the amount of elements $e_1$ and $e_2$ i…
mixture
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what happens to an atom if it gains 2 extra electrons? how does this ch…
The atom becomes a negatively - charged ion (anion) with a charge of - 2, and its chemical identity (the element it is) remains the same since the number of protons is unchanged.
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an atom has 12 protons, 12 neutrons, and 10 electrons. is it neutral or…
It is an ion. Since the net charge of the atom is +2 (12 protons with a total charge of +12 and 10 electrons with a total charge of -10, giving a net charge of \(+12-10 = + 2\)), …
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the ph of wines varies from 2.8 to 3.8. if the ph of a wine is too high…
California red wine has a hydrogen - ion concentration of $2.51\times 10^{-4}$ M. Italian white wine has a hydrogen - ion concentration of $1.26\times 10^{-3}$ M. For part (b), th…
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the ph reading of a sample of each substance is given. calculate the hy…
(a) $1.6\times 10^{-3}$ (b) $2.0\times 10^{-7}$
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the hydrogen ion concentration of a substance is given. calculate the p…
(a) 6.5 (b) 6.7
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6. deux ballons de verre identiques ont été remplis à la même températu…
La pression est plus élevée dans le ballon contenant le diazote.
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which of the following series of isoelectronic ions (mg²⁺, n³⁻, f⁻, si⁴…
C. $N^{3 - }>F^{-}>Si^{4+}>Mg^{2+}$
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which of the following elements has the smallest first ionization energ…
E. Cs
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rank the following atoms in order of increasing first ionization energi…
D. Rb < Mg < B < N < F
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which of the following atom(s) below has/have five valence electrons? a…
B. N
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answer: how many core electrons does an atom of beryllium (be) contain?…
C. 2
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what is the chemical formula of the molecule with the following structu…
$C_2H_4$
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which of the following is not a property affected by the effective nucl…
B. color
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considering periodic trends, valence electrons in which of the followin…
D. Ne
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which of the following is the electron configuration for ba? answer: a …
A. [Xe]6s²
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which element has the ground state electron configuration kr5s²4d¹⁰5p³?…
C. Sb
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21) give an example of each of three unusual properties of water.
1. Density: Ice (solid water) is less dense than liquid water. For example, ice floats on water in a glass. 2. Specific heat capacity: It takes a lot of heat to raise the temperat…
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16 which element is depicted from this orbital diagram? * (0.5 points) …
Neon (Ne)
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20) what particles are in the nucleus of an atom?
Protons and neutrons
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15 the orbital diagram for a ground state oxygen atom is: * (0.5 points…
D. 1s: $\uparrow\downarrow$, 2s: $\uparrow\downarrow$, 2p: $\uparrow\downarrow$ $\uparrow$ $\uparrow$
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6 if hydrogen has isotopes h - 1, h - 2, h - 3, what do the numbers rep…
A. mass number
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5 what does the number of neutrons affect? a element type b isotope typ…
B. isotope type
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describe the structure of a water molecule and explain how that structu…
A water molecule has a bent structure with a polar covalent bond due to the electronegativity difference between oxygen and hydrogen. This leads to hydrogen bonding between water …
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19) what is the nucleus of an atom?
The nucleus of an atom is the central, dense region that contains protons and neutrons and holds most of the atom's mass.
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decide whether these proposed lewis structures are reasonable. proposed…
1. For $[H - C\equiv C:]^{-}$: - No, it has the wrong number of valence electrons. The correct number is 10. 2. For $[:\ddot{Cl}=\ddot{O}:]^{-}$: - No, it has the wrong number of …
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3 silicon has isotopes: si - 28 (92%), si - 29 (5%), si - 30 (3%). whic…
A. 28.1 amu
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decide whether these proposed lewis structures are reasonable. proposed…
1. - For $N - N$: - No, it has the wrong number of valence electrons. The correct number is 10. - For $H - C\equiv N$: - Yes. - For $H - C - C - H$: - No, it has the right number …
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14 which element is depicted from this orbital diagram? * (0.5 points) …
Carbon
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which electron configuration represents a violation of hunds rule for a…
C.
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12 how many unpaired electrons does an atom of sulfur have? * (0.5 poin…
2
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decide whether these proposed lewis structures are reasonable. proposed…
For \(H\equiv Br\): No, it has the wrong number of valence electrons. The correct number is: 8 For \(F = O = F\): No, it has the right number of valence electrons but doesn't sati…
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which electron configuration represents a violation of the aufbau princ…
B.
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try again your answer is incorrect. . row 1: co₂: your answer is incorr…
For CO₂: No, it has the wrong number of valence electrons. The correct number is: 16 For H₂O: No, it has the wrong number of valence electrons. The correct number is: 8
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decide whether these proposed lewis structures are reasonable. proposed…
1. Yes. 2. No, it has the wrong number of valence electrons. The correct number is: 8 3. Yes.
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10 after the 5s subshell of an atom is filled with electrons, the next …
A. 4d subshell
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which choice lists two elements with electron configurations that are w…
C. Cr and Cu
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which statement best describes the rhyme schemes of the author to her b…
Bradstreet uses couplets for their overall rhyme scheme and structure; Wheatley uses couplets to enhance the poem as a song of praise for creation.
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neon has isotopes: ne-20 (90%), ne-21 (9%), ne-22 (1%). calculate its a…
C. 20.1 amu
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8 which orbital diagram is incorrect according to hunds rule? * (0.5 po…
III
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decide whether these proposed lewis structures are reasonable. proposed…
For $[\text{N}-\text{N}\equiv\text{N}]^-$: No, it has the wrong number of valence electrons. The correct number is 16. No, it has the right number of valence electrons but doesn't…
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7 which electron configuration represents a violation of the pauli excl…
D. 1s: ↑↓, 2s: ↑↑, 2p: ↑
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6 what is incorrect about this orbital diagram? * (0.5 points) both arr…
In the 2p box there should only be 1 electron in the first 2p box and one in the 2nd 2p box
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5 transition metal elements have atoms or ions with partially filled * …
C. d subshells
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drag the item from the item bank to its corresponding match. match the …
- Chemical potential energy transformed into radiant energy: Turning on a battery - operated light - Gravitational potential energy transformed into kinetic energy: A child going …
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4 which elements orbital diagram would end with this? * (0.5 points) 5d…
None, this violates Hund's rule
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match the scenario to the type of potential energy represented. gravita…
- Elastic: The string of a bow and arrow is pulled tight. - Chemical: A battery sits in an iPod before the iPod is turned on. - Electric: A positively charged particle is slowly m…
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question 15 (0.25 points) give the element symbol (blank 1) and the sup…
Blank # 1: Li Blank # 2: +1
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which electron configuration represents a violation of the pauli exclus…
B. 1s with two up - spin electrons, 2s with opposite - spin electrons, 2p empty
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question 14 (0.25 points) give the name of the polyatomic ion. do not i…
permanganate
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question 13 (0.25 points) give the name of the polyatomic ion. do not i…
chlorate
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2 the orbital diagram for a ground state nitrogen atom is: * (0.5 point…
A. $\uparrow\downarrow$ (1s), $\uparrow\downarrow$ (2s), $\uparrow$ $\uparrow$ $\uparrow$ (2p)
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question 12 (0.25 points) give the element symbol (blank 1) and the sup…
Blank # 1: K Blank # 2: +1
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1 which element is represented by the electronic orbital diagram given?…
Phosphorus
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question 11 (0.25 points) give the element symbol (blank 1) and the sup…
Blank # 1: Ni Blank # 2: $^{2 +}$
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question 10 (0.25 points) give the element symbol (blank 1) and the sup…
Blank #1: Al Blank #2: 3+
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question 9 (0.25 points) give the name of the polyatomic ion. do not in…
cyanide
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question 8 (0.25 points) give the name of the polyatomic ion. do not in…
carbonate
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question 7 (0.25 points) give the element symbol (blank 1) and the supe…
Blank # 1: Co Blank # 2: 3+
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question 6 (0.25 points) give the element symbol (blank 1) and the supe…
Blank # 1: F Blank # 2: 1-
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question 5 (0.25 points) give the name of the polyatomic ion. do not in…
nitrate
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question 4 (0.25 points) give the element symbol (blank 1) and the supe…
Blank # 1: S Blank # 2: 2-
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question 3 (0.25 points) give the name of the polyatomic ion. do not in…
dichromate
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question 2 (0.25 points) give the element symbol (blank 1) and the supe…
Blank # 1: Zn Blank # 2: 2+
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as a roller coaster moves downhill, which energy transformation takes p…
C. Potential → kinetic and thermal
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question 1 (0.25 points) give the name of the polyatomic ion. do not in…
perchlorate
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all of the following are strong points of comparison. check any you inc…
All of the above (assuming all the check - boxed options are to be considered as potential strong points of comparison)
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6. electron transitions • based on the three images below label which a…
Sodium (Na): 11 Aluminum (Al): 13 Carbon (C): 6 Silicon (Si): 14 Oxygen (O): 8 Chlorine (Cl): 17 Fluorine (F): 9 Phosphorus (P): 15 Lithium (Li): 3
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read the highlighted squares from left to right to find the hidden code…
TLLWPD4C (Note: This is based on sample answers for illustration, actual answer depends on correct crossword fill - in)
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question 14 choose the correct signal word from the sds for all of the …
a. Nonhazardous b. Nonhazardous c. Warning d. Nonhazardous e. Nonhazardous
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question 13 5 pts calcium chloride has been designated category 2a for …
Rinse cautiously with water for several minutes with contact lenses removed (if possible)
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question 12 2.5 pts in vacuum filtration, if your filtrate is cloudy, t…
B. False
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question 11 2.5 pts in vacuum filtration, you should dump out the liqui…
B. False
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question 10 2.5 pts in vacuum filtration, it is okay if some of the liq…
B. False
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question 9 2.5 pts in vacuum filtration, it is not okay to operate the …
True
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question 8 what should you not do with a desiccator? (select all that a…
A. Keep the lid off for long periods of time D. Set the lid on the table E. Store water inside F. Lift up on the lid
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question 6 13 pts to determine the concentration of chloride ion (cl⁻) …
238 mg/L
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how many valence electrons does each atom have in the bohr diagrams? f …
F: 7 Cl: 7 Br: 7 I: 7
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question 4 10 pts balance the following double displacement reaction by…
$2$ $(NH_4)_3PO_4(aq)+3$ $BaS(aq)\to3$ $(NH_4)_2S + 1$ $Ba_3(PO_4)_2$ So the coefficients are: [2], [3], [3], [1]
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identify all spectator ions in the reaction shown below. you may select…
Potassium ion, Nitrate ion
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question 2 10 pts a precipitation reaction occurs when potassium carbon…
$K_2CO_3(aq)+MgCl_2(aq) ightarrow MgCO_3(s) + 2KCl(aq)$
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the treatment of water involves several steps such as screening, word 1…
[word 1]: Sedimentation [word 2]: Objective [word 3]: Double displacement [word 4]: Precipitate [word 5]: Hardness [word 6]: Stoichiometry
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which of the following aqueous solutions are highly ionized? a) sugars …
B. strong acids
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in order for a solution to conduct electricity, the solution must have.…
C. a separation of ions
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question 8 (1 point) listen which of the molecules is polar? a) f₂ b) h…
B. $H_2O$
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question 7 (1 point) listen which of the following is ionic? a) scl₂ b)…
d) $Al_2O_3$
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question 6 (1 point) listen when a covalent compound melts, ... a) cova…
B. individual molecules are moved farther apart
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the solubility of each compound will be determined by mixing the compou…
B. 6 - well plate
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which of the following is true? a) none of the solutions will conduct e…
d) If an ionic compound is soluble in water, it will conduct electricity.
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question 3 (1 point) listen water is a universal solvent because... a) …
A. it can dissolve a large amount of ionic and polar compounds.
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question 2 (1 point) listen which of the following solutions would not …
A. non - electrolyte
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when dissolved in water, which of the following forms a molecular solut…
B. $CH_3OH$
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9/29 bath bomb day 1: related phenomena due oct 1 by 8am points 5 submi…
- Effervescence in Alka - Seltzer tablets - Fizzing of baking soda and vinegar reaction - Dissolution and gas - release in antacid tablets
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write a paragraph comparing and contrasting how the poets use topic, rh…
Poems vary in how they use topics, rhyme - schemes, and figurative language to convey themes. Some may have similar topics but different rhyme - schemes that alter the tone. For e…
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which statements describe elements? check all that apply. atoms of the …
- Atoms of the same element always have the same number of electrons. - Atoms of the same element can have different numbers of neutrons. - Atoms of the same element always have t…
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4) water molecules are composed of a. two oxygen atoms and two hydrogen…
B. one oxygen atom and two hydrogen atoms
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2) the central core of every atom, containing particles called protons …
C. nucleus
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elements in group 2 are all called alkaline earth metals. what is most …
which chemical properties they have