化学
化学反应、化学计量、分子结构与元素性质。
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of an initial amount of 2000 g of lead - 210, how much will remain in 1…
$35.5$
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review the claim and the two pieces of evidence. chewing gum can improv…
Evidence B does not come from a credible source. It is based on the opinion of one person who is not an expert and has not done research.
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consider this claim: chewing gum can improve our alertness and lower ou…
A. In a study of forty participants, those who chewed gum while performing stressful tasks had lower levels of anxiety and higher levels of alertness than those not chewing gum.
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14. how many total electrons does k have? a. 17 b. 18 c. 19 d. 20 15. h…
14. C. 19 15. A. 9 16. B. 10 17. 9
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9. how many electron shells does n have? a. 1 b. 2 c. 3 d. 4 10. how ma…
9. B. 2 10. B. 2 11. 7 12. 6 13. 8
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5. how many valence electrons does magnesium have? a 1 b 6 c 4 d 2 6. h…
5. D. 2 6. A. 7 7. A. 7 8. B. 2
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1. what is the periodic symbol for sulfur? a. s b. sa c. s d. su 2. wha…
1. C. S 2. A. Si 3. D. Potassium 4. A. Carbon
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19. which of the following is not a typical cause of anorexia nervosa? …
# Breve explicación: La anorexia nerviosa es un trastorno mental complejo. La baja autoestima, el deseo intenso de complacer a los demás y la falta de químicos reguladores del est…
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what has the greatest ionization energy? mg ca na k
Mg
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what has the greatest ionic radius? br k cl ar what has the greatest el…
1. Br 2. Cl 3. K 4. K
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what has the greatest atomic radius? ne mg ca fr what has the greatest …
1. What has the greatest Atomic Radius? Fr 2. What has the greatest Ionic Radius? Fr 3. What has the greatest Ionization Energy? Ne 4. What has the greatest Electronegativity? Mg
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what has the greatest atomic radius? ar s mg k what has the greatest io…
1. What has the greatest Atomic Radius? K 2. What has the greatest Ionic Radius? K 3. What has the greatest Ionization Energy? Ar 4. What has the greatest Electronegativity? S
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the meniscus is the lowest part of the curve, and that is where you tak…
# Explicación: ## Paso 1: Identificar la graduación del cilindro graduado El cilindro graduado tiene una graduación de 1 mL entre cada línea. ## Paso 2: Leer la posición del menis…
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what has the greatest atomic radius? o n si al what has the greatest io…
1. What has the greatest atomic radius? Al 2. What has the greatest ionic radius? O 3. What has the greatest ionization energy? O 4. What has the greatest electronegativity? O
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what has the greatest atomic radius? he cl sr cs what has the greatest …
1. What has the greatest Atomic Radius? Cs 2. What has the greatest Ionic Radius? Cs 3. What has the greatest Ionization Energy? He 4. What has the greatest Electronegativity? Cl
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in a lab experiment, students had four samples of elements. they made o…
D
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fingerprint reliability and validity 1. in the 1995 test given to 156 f…
1. Variability and error potential among examiners. 2. Misidentified Mayfield's fingerprint; exonerated when real perpetrator identified. 3. Lack of standardization, subjectivity,…
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what has the greatest atomic radius? f ne ca k what has the greatest io…
1. What has the greatest Atomic Radius? - D. K 2. What has the greatest Ionic Radius? - A. F 3. What has the greatest Ionization Energy? - B. Ne 4. What has the greatest Electrone…
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20 multiple choice 10 points mucus, tears, saliva, and hair are all exa…
D. Mechanical barriers
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nh3 is nitrogen trihydride (ammonia) and bf3 is boron trifluoride. what…
Aluminum chloride - It does not have the prefix "tri -" since it is ionic.
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the alkali metals, found in group 1 of the periodic table, are very rea…
Elements in the same group have the same number of valence electrons. Sodium in group 1 has 1 valence electron and chlorine in group 17 has 7 valence electrons. Sodium donates its…
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what is a column called in the periodic table and what do the elements …
What is a column called in the periodic table: Group. What do the elements in each column have in common: The same number of valence electrons. Based on what the periodic table ca…
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significant digits are used in chemistry to show the ______________ of …
precision
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which nonmetal would an ion of ca²⁺ most likely ionically bond with in …
B. one atom of oxygen
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sodium ions are used by your body every time you move a muscle. the dif…
C. a sodium atom has one fewer electron.
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what is the answer expressed with the correct significant digits for: 7…
3.4 g/cm³
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the decomposition of dinitrogen tetroxide into nitrogen gas and oxygen …
B. $N_2O_4(g) ightarrow N_2(g)+2O_2(g)$
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what coefficients are needed to balance the chemical equation? nabr + c…
B. 2,1,2,1
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4al + 3o₂ → 2al₂o₃ question: in the reaction and the product(s) is/are …
D. aluminum oxide
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a solution with a range of ph of 0 - 6 is a base alkaline neutral solut…
D. ácido
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43. someone might not feel well after riding a fast elevator in a tall …
B. the semi - circular canals (rotational equilibrium)
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atomic structure 7 periods/rows. the number of energy levels/shells con…
The periodic table arranges elements by periods (rows) corresponding to energy levels. Metals, on the left of the "stair - step" line (except hydrogen), are conductors, malleable,…
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directions: use the periodic table to fill in the below chart. name 6.4…
| Element | Symbol | Atomic Number | # of Protons | # of Electrons | Atomic Mass | Rounded Atomic Mass | # of Neutrons (show work) | Period | | ---- | ---- | ---- | ---- | ---- | …
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directions: use a periodic table to find the information asked for belo…
1. Calcium: 20, Iron: 26, Gold: 79, Uranium: 92 2. Calcium: 40.08, Iron: 55.85, Uranium: 238.03, Copper: 63.55 3. Calcium: 20, Gold: 79, Copper: 29, Iron: 26 4. Gold: 79, Iron: 26…
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which of these illustrations best represents the particles in a gas? a …
For the first question: a For the second question: a, c, d, f
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put some tap water in two cups. stir a bit of table salt into one of th…
# Explicación: ## Paso 1: Comprender la conductividad eléctrica La sal disuelta en agua forma iones. Estos iones permiten el flujo de electricidad. ## Paso 2: Comparar los dos tip…
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50. baking soda is chemically known as: na₂co₃ nahco₃ caco₃ khco₃
B. NaHCO₃
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using the periodic table, what can you conclude about the classificatio…
C. Iodine is a nonmetal and is dull, brittle, poor conductor of heat and electricity, forms anions in aqueous solution, and is a solid at room temperature.
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48. chalk is mainly composed of: caco₃ na₂co₃ k₂co₃ mgco₃ 49. the formu…
48. $CaCO_3$ 49. $H_2O$
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46. the formula for potassium oxide is: ko k₂o k₂o₂ ko₂ 47. how many ox…
46. B. $K_{2}O$ 47. C. 12
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the diagram shown is an example of the element. a boron. b bromine. c n…
A. boron
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44. the formula of slaked lime is: cao ca(oh)₂ cah₂ caho₂ 45. sodium ox…
44. B. $Ca(OH)_2$ 45. B. $Na_2O$
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chapter 4.4 - 4.5 vocabulary: fill in the blank name: ____________ pd__…
1. Periodic Table 2. Group 3. Alkali Metal 4. Alkaline Earth Metal 5. Halogen 6. Noble gas 7. Transition Metal 8. Metal 9. Nonmetal 10. Metalloid 11. Law of Conservation of Mass 1…
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which elements will bond ionically with barium such that the formula wo…
B. Chlorine, iodine, and fluorine
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e - cigarette use can prevent the lungs from recovering properly from v…
- Question 13: True - Question 14: No cigarette, filtered or unfiltered, is truly safe - Question 15: Approximately 90%
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e - cigarette use can prevent the lungs from recovering properly from v…
Question 13: True Question 14: No cigarette, filtered or unfiltered, is truly safe Question 15: Approximately 90%
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this diagram represents the synthesis of nitrogen monoxide. write a bal…
$N_2(g)+O_2(g) ightarrow 2NO(g)$
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there is a 100% safe way to use tobacco. true false question 5 (1 point…
False False Leads to changes in brain chemistry
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when magnesium (mg2+) and fluorine (f1 -) combine in an ionic bond, the…
B. $MgF_{2}$
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during a physical science lab investigating chemical reactions, several…
C. 10 grams
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the element hydrogen has three naturally occurring isotopes, h - 1, h -…
1 proton, 2 neutrons, 1 electron (Option B)
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a calcium bromide compound is represented by which formula? a ca2br b c…
The formula for calcium bromide is $CaBr_{2}$, so the correct option is not shown in the provided description (assuming the correct one should be $CaBr_{2}$ among the choices in t…
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6. ____ displays use organic molecules that are self - illuminating and…
a. OLED
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the formation of lithium fluoride (seen here) is due to a a stronger pu…
B. increased stability in the completion of fluorine's outer shell.
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a student is told that both energy and mass must be conserved in every …
D. Gas escapes, indicating mass loss as it leaves the container.
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question 11 (3 points) 218 84 po → 0 -1 e⁻ + word bank: 218 bi at 85 83…
Blank 1: 218 Blank 2: At Blank 3: 85
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you are given two unknown solutions, a and b. one of the solutions cont…
A. A contains sugar and B contains salt, because salt is ionic and is a good conductor of electricity.
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which formulas and their respective names do not match? i) bao barium h…
A. (i) only
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ms. jameson is using \sonnet 18\ by william shakespeare to teach her st…
A. aa
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a sample of sand is taken at random from the shore of a lake. the table…
C. The proportion of garnet will be less than 0.1.
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which type of medicine kills disease - causing bacteria to prevent infe…
A. Antibiotics
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6. calculate the relative atomic mass for germanium $_{32}^{70}ge = 20.…
The relative atomic mass of Germanium is approximately $72.69$ and the relative atomic mass of Selenium is approximately $79.04$
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5. calculate the relative atomic mass for titanium using the following …
47.92
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3. calculate the relative atomic mass for magnesium using the following…
The relative atomic mass of magnesium is approximately $24.31$ and the relative atomic mass of silicon is approximately $28.11$.
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sample response: one way this poem reflects dickinsons style is that it…
The poem is written in the first person. The poem uses four - line stanzas. The poem plays with rhyme scheme.
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1. calculate the relative atomic mass for nitrogen using the formula $^…
1. The relative atomic mass of nitrogen is $14.0037$. 2. The relative atomic mass of boron is $10.801$.
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1. $_{91}^{231}pa\ ightarrow _{2}^{4}he + _{89}^{227}\\\\2. $_{95}^{241…
1. $^{231}_{91}Pa ightarrow^{4}_{2}He+^{227}_{89}Ac$ 2. $^{241}_{95}Am ightarrow^{4}_{2}He+^{237}_{93}Np$ 3. $^{292}_{94}Pu ightarrow^{4}_{2}He+^{288}_{92}U$ 4. $^{226}_{88}Ra igh…
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which term refers to the substance that is dissolved into another subst…
A. solute
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question 31 not yet answered points out of 3.00 flag question which kin…
B. old vs. new C. dark vs. light E. opaque vs. transparent
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which quantities are inversely proportional if other variables are held…
volume and pressure
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there are 500 molecules in an airtight bucket, and the volume is held c…
Adding 100 more molecules and increasing the temperature by 10K
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the boiling point of methanol is 64.7°c. its melting point is -97.6°c. …
B. liquid
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question 26 not yet answered points out of 3.00 flag question what kind…
D. monochromatic
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question #3 not yet answered points out of 3.00 flag question are the f…
A. both
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question 8 not yet answered points out of 3.00 flag question select the…
a. the overall shapes of the walls and ceiling/roof are geometric, but these forms are made up of smaller organic shapes c. the ceiling materials and lighting design are lighter i…
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22. ____________ metal 23. ____________ chlorine 24. ____________ metal…
22. g. loses electrons in bonding 23. c. a halogen 24. d. make good semiconductors 25. b. metals with unpredictable properties 26. e. alkali metals 27. f. has a full outer energy …
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select the 2 statements that best match the visual appearance of this t…
b. The surface of the kettle has implied texture. e. The circular and semi - circular forms used in the tea kettle are geometric.
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29 what do the dots in lewis dot diagram represent? a protons b valence…
B. Valence electrons
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28 how many valence electrons does chlorine (cl) have based in lewis do…
B. 7
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27. what do atoms of elements that are in the same group share? a numbe…
C. number of valence electrons
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small - scale lab i & e standard: 1d now what do i do? purpose to solve…
The value of $m_{single - drop,mg}$ after performing above steps.
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when naming binary ionic compounds with metals that typically form only…
1. False 2. The formula is incorrect because the charges were not balanced; the correct formula is $MgCl_{2}$
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the iupac name for the ionic compound k₃n is tripotassium nitride. * 1 …
1. False 2. A. \(Pb(NO_3)_2\)
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25 if an atom has 19 protons and 20 neutrons, what is the atomic number…
A. 19
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supply chain questions - due tomorrow!! toothpaste requires an abrasive…
B. calcium carbonate
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analyze using your experimental data, record the answers to the followi…
1. Cannot calculate. 2. Cannot calculate. 3. $1000\ mg/cm^{3}$, $1000\ mg/mL$ 4. Cannot calculate. 5. Cannot calculate. 6. Newer penny has more low - density zinc.
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given the iupac name lead(ii) nitrate, what is the correct chemical for…
1. $Pb(NO_3)_2$ 2. False
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supply chain questions - due tomorrow!! propylene glycol helps retain w…
D. deice the wings of airplanes
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22 according to the bohr model above, what is the atomic mass of sodium…
C. 23
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what is the correct chemical formula for the ionic compound tin(iv) oxi…
1. $SnO_{2}$ 2. True 3. $Ca_{3}(PO_{4})_{2}$
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iron can form ions with charges of +2 and +3. what roman numeral is use…
1. B. III 2. C. iron(II) chloride
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21 if an atom has 18 protons and 22 neutrons, what is the atomic mass? …
B. 40
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what is the correct iupac name for the ionic compound with the chemical…
1. iron(II) chloride 2. True
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if an ionic compound has the chemical formula mg₃n₂, what are the charg…
1. Mg²⁺, N³⁻ 2. Sodium sulfide
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chemistry_quiz 2 locked mode is on. to avoid losing your progress, comp…
1 x 10^-12 (the last option)
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the criss - cross method involves exchanging the numerical value of the…
1. True 2. False
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20 analyze the bohr model below. 6. which three statements best describ…
A. The mass number is 4 and the atomic number is 2. B. This element has a full energy level. C. This element has 2 valence electrons.
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when applying the criss - cross method, the signs (+ or -) of the ionic…
1. A. False 2. B. KCl
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chemistry_quiz 2 locked mode is on. to avoid losing your progress, comp…
D. Coefficient can be positive or negative.
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which of these shows a single displacement reaction? ab + cd → ad + cb …
1. C. $A + BC ightarrow AC + B$ 2. C. Synthesis