化学
化学反应、化学计量、分子结构与元素性质。
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select the correct answer. the image shows a portion of the periodic ta…
C. fluorine and chlorine
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select the correct answer in the periodic table of elements, what do al…
C. Each element is an alkaline earth metal
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complete the following information for chlorine # of protons # of elect…
| Element | # of Protons | # of Electrons | # of Neutrons | Total Number of Particles | Group | Period | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | Chlorine | 17 | 17 | …
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complete the following information for neon. # of protons # of electron…
| # OF PROTONS | # OF ELECTRONS | # OF NEUTRONS | TOTAL NUMBER OF PARTICLES | GROUP | PERIOD | | ---- | ---- | ---- | ---- | ---- | ---- | | 10 | 10 | 10 | 30 | 18 | 2 |
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complete the following information for fluorine # of protons 9 # of ele…
| Element | # of Protons | # of Electrons | # of Neutrons | Total Number of Particles | Group | Period | |---|---|---|---|---|---|---| | Sodium | 11 | 11 | 12 | 34 | 1 | 3 | | Mag…
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chemistry: fundamentals and principles presented by macmillan learning.…
Metals: Cu, K, V Nonmetals: Kr, I, O
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question 15 of 16 match each element to the appropriate group on the pe…
Alkali metal: Lithium, Francium Alkaline earth metal: Barium, Beryllium Halogen: Fluorine, Bromine Noble gas: Krypton, Helium
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complete the following information for helium. # of protons 2 # of elec…
| Element | # of Protons | # of Electrons | # of Neutrons | Total Number of Particles | Group | Period | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | Helium | 2 | 2 | 2 | …
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question 13 of 16 the statements either define or are closely related t…
1. Group 2. Period 3. Period 4. Group
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complete the following information for lithium. # of protons # of elect…
| # OF PROTONS | # OF ELECTRONS | # OF NEUTRONS | TOTAL NUMBER OF PARTICLES | GROUP | PERIOD | | ---- | ---- | ---- | ---- | ---- | ---- | | 3 | 3 | 4 | 10 | 1 | 2 |
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determine the element symbol, mass number, and charge for an atom or io…
element symbol: Sr mass number: 87 charge: +2
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determine the element symbol, mass number, and charge for an atom or io…
# Explanation: ## Step1: Identify the element The atomic number is equal to the number of protons. With 38 protons, the element is strontium, symbol Sr. ##[SSE Completed, Client C…
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wendy complete the following information for hydrogen. mass - proton # …
| # OF PROTONS | # OF ELECTRONS | # OF NEUTRONS | TOTAL NUMBER OF PARTICLES | GROUP | PERIOD | | ---- | ---- | ---- | ---- | ---- | ---- | | 1 | 1 | 0 | 2 | 1 | 1 |
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determine the number of neutrons, protons, and electrons for a bromide …
number of neutrons (bromide ion): 42 number of protons (bromide ion): 35 number of electrons (bromide ion): 36 element symbol (second ion): Fe number of protons (second ion): 26 n…
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question 11 of 10 > chemistry: fundamentals and principles presented by…
1. + 3 2. 0 3. - 3 4. + 1
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question 2 why is water tested also when testing for carbohydrates? it …
Question 2: Water is tested as a control to provide a baseline for comparison since it does not contain carbohydrates. What chemical indicator is used to test for the presence of …
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question 10 of 10 > use the atom - builder interactive to classify each…
Positive ion: three protons, three neutrons, and two electrons; one proton, one neutron, and zero electrons Negative ion: one proton, zero neutrons, and two electrons Neutral atom…
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/th grade poetry vocabulary worksheet name and class period_ part a - m…
1. C 2. D 3. E 4. B 5. A
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the image shows a representative sample of 50 atoms of a fictious eleme…
(You need to count the actual number of spheres in the image to get the specific values. For example, if there are 20 red spheres, 15 light - blue spheres, and 15 dark - blue sphe…
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question 3 of 16 the image shows a representative sample of 50 atoms of…
Le - 19: 20% Le - 17: 24% Le - 15: 56% Average atomic mass of Le: 16.80728 u
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noemi is writing an essay on organic foods. she wishes to include prope…
She could summarize the ideas from the source. She could paraphrase the ideas from the source. She could directly quote the ideas from the source.
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how many grams of neon, ne, would contain the same number of atoms as 2…
$20.18$
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13. list three common household items. identify one chemical property o…
1. Vinegar, its chemical property is reactivity with baking - soda. 2. Baking Soda, its chemical property is thermal decomposition. 3. Steel Wool, its chemical property is rusting…
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how many atoms are in 165 g of calcium? 165 g = atoms
$2.48\times 10^{24}$
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first and last name:alyssa lolley block:3rd assignment 9 the water cris…
Fossil Water - D Desalination - A Groundwater - C Replenish - F Tributaries - G Irrigation - B Scarcity - E Pollution - H
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calculate the number of atoms in a 5.39×10³ g sample of lithium. number…
$4.687\times 10^{26}$
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question 11 of 14 > a zinc ring is composed of 2.59×10²³ atoms. calcula…
$28.1$ g
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for the each element, convert the given mole amount to grams. how many …
For potassium: 2.21 g For cobalt: 32.4 g For selenium: 62.4 g
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convert 1.00 g of each element to moles. how many moles of magnesium ar…
$1.00\ g\ Mg\approx0.0411\ mol$ $1.00\ g\ Mn\approx0.0182\ mol$ $1.00\ g\ He\approx0.2498\ mol$
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material safety data sheets 1. locate and demonstrate the use of materi…
A. To provide chemical - related safety info including hazards, handling, storage, and emergency response. B. For example, for ethanol, search on manufacturer or safety database w…
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isotopes of the same element have different numbers of _. neutrons prot…
A. neutrons
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determine the chemical formula for each of the compounds. sodium perchl…
sodium perchlorate: $NaClO_4$ potassium permanganate: $KMnO_4$ calcium sulfate: $CaSO_4$ lithium cyanide: $LiCN$
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the modern atomic theory has been updated over the years as new observa…
The changes make the theory stronger because it has been tested and edited multiple times, making it more durable.
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determine the formula for each compound from its name. calcium sulfite:
$CaSO_{3}$
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match the scientist to his contribution to the atomic theory. match ter…
Rutherford - C Dalton - B Schrodinger - A
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determine the formula for each compound from its name. calcium sulfate:…
calcium sulfate: $CaSO_{4}$ chromium(III) fluoride: $CrF_{3}$ tetraphosphorus decoxide: $P_{4}O_{10}$
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determine the name for each compound from its formulas. k₂o: potassium …
Dinitrogen pentoxide
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determine the name for each compound from its formulas. k₂o: ni₂se₃: n₂…
Potassium oxide Nickel(III) selenide Dinitrogen pentoxide
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determine the name for each compound from its formulas. k₂o: ni₂se₃: n₂…
$K_2O$: Potassium oxide $Ni_2Se_3$: Nickel(III) selenide $N_2O_5$: Dinitrogen pentoxide
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write the formula for hydrobromic acid. formula:
HBr
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propiedades físicas y químicas definición dureza intensidad conductivid…
d. El silicio reacciona con el flúor para formar tetraflúoruro de silicio.
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4. ch₄ • elementos: • número de átomos: • relación: 5. c₆h₁₂o₆ • elemen…
# Explanation: ## Paso 1: Analizar los átomos en CH₄ El compuesto CH₄ está formado por carbono (C) e hidrógeno (H). Tiene 1 átomo de carbono y 4 átomos de hidrógeno. La relación d…
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write the formula for each compound. capitalization and subscripts are …
selenium tetrafluoride: $SeF_4$ oxygen difluoride: $OF_2$ dinitrogen monoxide: $N_2O$ phosphorus trichloride: $PCl_3$
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which sentence states a fact? crystals take about a week to form from a…
Crystals take about a week to form from a solution of water and sugar.
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give the systematic name of each covalent compound. spelling counts. sf…
SF₄: Sulfur tetrafluoride P₄S₃: Tetraphosphorus trisulfide CO: Carbon monoxide P₃N₅: Triphosphorus pentanitride
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tarea de trabajo de ciencias de séptimo grado: proporciones de átomos e…
# Explicación: ## Paso 1: Identificar elementos en H₂O El agua está formada por hidrógeno (H) y oxígeno (O). ## Paso 2: Contar átomos en H₂O Hay 2 átomos de hidrógeno y 1 átomo de…
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give the systematic name of each of the compounds. fecl₂: pbo₂: cubr: a…
1. Iron(II) chloride 2. Lead(IV) oxide 3. Copper(I) bromide 4. Gold(III) sulfide
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automotive chemicals and hazardous waste 1. define the following terms.…
C. A substance that can easily catch fire and burn. D. A substance that can destroy or damage other materials by chemical reaction, often by eating away at them. E. A substance th…
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7. alicias cheapskate boyfriend gave her a ring he claims is 24 carat g…
The volume of the ring is $1.5\mathrm{mL}$, the density of the ring is approximately $10.19\mathrm{g/mL}$ (it is likely not 24 - carat gold), and the mass of the solid object in t…
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1. distinguish between the characteristics of an unweathered rock and t…
1. An unweathered rock has smooth surfaces, sharp edges, and uniform color. A highly - weathered rock has rough surfaces, rounded edges, and color variations. 2. Chemical weatheri…
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automotive chemicals and hazardous waste 1. define the following terms.…
A. A substance or material with potential to harm human health or the environment. B. A substance that can produce adverse effects on living organisms.
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melting point data | compound | nacl | kcl | rbcl | cscl | mgf₂ | mgcl₂…
3. Los compuestos con altos puntos de fusión son iónicos. La fuerza de atracción entre iones depende de la carga y el radio atómico. Iones con carga más alta y radio más pequeño d…
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6. katie is doing a chemistry experiment and has 50 ml of a 25% solutio…
$6.25$ ml
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4. which type of fire extinguisher should be used for the following cla…
A. Water - based or dry - chemical fire extinguisher B. Dry - chemical, carbon dioxide, or foam fire extinguisher
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name date class melting point data compound nacl kcl rbcl cscl mgf₂ mgc…
Los compuestos con puntos de fusión altos son compuestos iónicos. La tendencia en los puntos de fusión se debe a la carga de los iones y el radio atómico. Compuestos con iones de …
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mixture separations 3. distillation separates mixtures based on _. 4. f…
3. Boiling - points 4. Particle size 5. Affinities for stationary and mobile phases 6. Physical
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2. h₂o particles go from being able to slide about, with a fixed volume…
Phase change: Freezing Formula: $H_2O_{(l)}\to H_2O_{(s)}$
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2. h₂o particles go from being able to slide about, with a fixed volume…
Freezing
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14. what are the three ways in which atoms with incomplete valence shel…
Ionic bonding, covalent bonding, hydrogen bonding.
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question 5 of 29 determine the vant hoff factor (i) for the following s…
1.128 M $C_2H_5OH$: $i = 1$ 0.073 M $Mg(NO_3)_2$: $i = 3$ 0.30 M $NaCl$: $i = 2$ 0.0032 M $CaBr_2$: $i = 3$
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question 2 of 29 determine the vant hoff factor (i) for the following s…
0.35 M NaCl: $i = 2$ 0.0038 M $MgBr_{2}$: $i = 3$ 1.269 M $C_{6}H_{12}O_{6}$: $i = 1$ 0.087 M $Ca(ClO_{4})_{2}$: $i = 3$
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(d) ____ c₄h₆o₃+____ h₂o→____ c₂h₄o₂ (e) ____ c₂h₄+____ o₂→____ co₂+___…
(d) 1, 1, 2 (e) 1, 3, 2, 2 (f) 1, 6, 4, 5 (g) 1, 11, 7, 8 (h) 4, 4, 1, 8
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determine whether each statement is true or false. attractive forces be…
1. True 2. False 3. False 4. True 5. False
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12. fill in the missing items in the table below. | name | symbol | z |…
| NAME | SYMBOL | Z | A | # PROTONS | # ELECTRONS | # NEUTRONS | ISOTOPIC SYMBOL | | --- | --- | --- | --- | --- | --- | --- | --- | | Sodium | Na | 11 | 23 | 11 | 11 | 12 | $_{11…
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11. if you know only the following information can you always determine…
a. Yes b. No c. Yes d. No
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10. name the element which has the following numbers of particles: a. 2…
a. Iron (Fe) b. Iodine (I) c. Helium (He) d. Calcium (Ca) e. Lead (Pb) f. Hydrogen (H)
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look at this sentence: car manufacturers have been investing in new ene…
2. a higher or unusual cost of something
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when hydrogen and oxygen combine to form water, water would be * 0/1 ne…
B. a product
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5. aluminum foil is often incorrectly termed tin foil. if the density o…
The thickness of the tin foil is approximately $0.0037$ cm.
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article summary changing tastes, preferences, and demographics in the r…
rising average costs and long - run economic profits.
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8. give the symbol of and the number of electrons in a neutral atom of:…
Uranium: U, 92 Iodine: I, 53 Xenon: Xe, 54 Boron: B, 5 Chlorine: Cl, 17
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3. a piece of green jade has a mass of 26.123 g. if the sample of jade …
$0.522$ g/$cm^{3}$ (rounded to three - significant figures) ### 4.
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study the chemical equation below. then answer questions 1 - 4. (s = su…
1. No, because the number of sulfur and oxygen atoms is not the same on both sides of the chemical equation. 2. Tatum is correct. Because in $2SO_2$, the number of sulfur and oxyg…
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click to fix any capitalization errors below. click \submit answer\ if …
No capitalization errors.
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study the chemical equation below. then answer questions 1 - 4. (s = su…
No, because the number of sulfur and oxygen atoms is not the same on both sides of the chemical equation.
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the basic unit of matter that cannot be broken down further by chemical…
1. C. atom 2. B. chemical reaction 3. A. reactant
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a substance formed by a chemical reaction; found on the right - hand si…
1. B. product 2. B. yield 3. A. chemical symbol
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the number at the beginning of a chemical symbol or formula that indica…
1. D. coefficient 2. D. chemical formula 3. D. periodic table
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the small number that comes after a chemical symbol or set of parenthes…
1. D. subscript 2. B. chemical equation 3. D. molecule
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what is required to balance the following equation? * __h₂ + __o₂ → __h…
C. 2, 1, 2
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which of the following atoms are involved in this reaction? * 2na + cl₂…
1. C. Sodium and chlorine 2. C. $Fe_2O_3$ 3. A. A chemical reaction has occurred 4. None of the above (the correct coefficients are 2, 1, 2)
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which of the following is not evidence of a chemical reaction? * a. cha…
1. C. Melting of ice 2. B. 2 3. C. Coefficient
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6. the mass number is used to calculate the number of _______________ i…
neutrons; atomic number; mass number
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which statement describes the law of conservation of mass? * 10 points …
1. C. Matter cannot be created or destroyed 2. D. Reactants 3. B. The number of atoms of each element is equal on both sides
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5. the ______________ of an element is the total number of protons and …
mass - number; nucleus
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which statement best compares acids and bases? * 10 points a. acids are…
1. B. Acids and bases are both conductors of electricity 2. C. Determine its pH 3. A. Acids produce more hydrogen ions, bases produce more hydroxide ions
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4. the ______________ of an element is the average mass of an element’s…
atomic mass; abundance
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4. a rubber stopper has a mass of 7.452 g and displaces 6.0 ml of water…
(4) \( 1.242\ g/mL \) (5) No length values provided in the text for answer (6) \( 8.89\ g/cm^{3} \) (7) \( 0.00102\ cm \) (8) No specific experiment - related info given for safet…
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which property is shared by both acids and bases? * a. sour taste b. sl…
1. C. Electrical conductivity 2. C. Acids have a lower pH than water 3. A. The fluid is a base
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3. the atomic number tells you the number of ____________ in one atom o…
protons; electrons; same
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an unknown substance has a ph of 4. which statement is true? * a. it is…
1. D. It is an acid 2. C. Slippery texture 3. A. The liquid is an acid
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2. the number of protons in one atom of an element determines the atom’…
Atomic number; chemical properties
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prelaboratory assignment 1. provide the key - term that corresponds to …
(a) density (b) weighing by difference (c) uncertainty (d) condition (e) meniscus (f) volume by displacement ### 2.
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basic atomic structure worksheet 1. the 3 particles of the atom are: a.…
1. a. Proton b. Neutron c. Electron Their respective charges are: a. Positive b. Neutral c. Negative
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click to fix any capitalization errors below. click \submit answer\ if …
Moana cooled liquid nitrogen and caused an explosion in the chemistry lab.
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1. provide the key - term that corresponds to each of the following def…
(a) density (b) weighing by difference (c) uncertainty (d) conditioning (e) meniscus (f) volume by displacement 2.
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what property is shown when an object strip off some of its electrons w…
b) Oxidation
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which of the following is a property of nonmetals? poor heat and electr…
B. ALL of these
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what is unique about the noble gas elements? they form diatomic molecul…
They are unreactive
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who was the scientist who proposed the plum pudding model? thomson dalt…
A. Thomson