化学
化学反应、化学计量、分子结构与元素性质。
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substance x is brown black and sticky. it is formed by a condensation p…
Tar
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nitrogen 14.007 what is the chemical symbol of this element? what is th…
**Nitrogen**: Atomic number: 7 Chemical symbol: N Name: Nitrogen Atomic mass: 14.007 Neutrons: 7 **Carbon**: Protons: 6 Electrons: 6 Atomic number: 6 Chemical symbol: C Name: Carb…
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below is a model of a portion of the periodic table of elements. this p…
How many protons does this element have? 7 How many electrons does this element have? 7 What is the atomic number of this element? 7 What is the chemical symbol of this element? N…
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7. lair est composé de plusieurs gaz formant un mélange homogène. parmi…
a) Faux. L'azote est un élément chimique et le gaz d'azote est composé de molécules $N_2$ (deux atomes d'azote identiques). b) Vrai. c) Vrai. d) Vrai. e) Vrai.
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b) soit le changement chimique suivant. s + o₂ → so₂ est - ce que le mé…
# Explications brèves: Le mélange de soufre (S) et d'oxygène (O₂) n'a pas les mêmes propriétés que le dioxyde de soufre (SO₂) car selon la théorie de Dalton, les composés chimique…
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5. john dalton, scientifique anglais, a décrit latome à travers un modè…
Oui, c'est le même aluminium. Les atomes d'un même élément sont identiques selon la théorie de Dalton, et l'aluminium est un élément.
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2. which of the following are amphoteric in aqueous solution? for those…
The amphoteric species are $H_2PO_4^-$, $HC_2O_4^-$ and $HCO_3^-$. For $H_2PO_4^-$: As an acid: $H_2PO_4^- ightleftharpoons HPO_4^{2 -}+H^+$; as a base: $H_2PO_4^- + H^+ ightlefth…
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4. illustre les molécules suivantes selon le modèle atomique de dalton.…
# Explications étape par étape: ## Étape 1: Comprendre le modèle atomique de Dalton Le modèle atomique de Dalton considère les atomes comme des billes indestructibles et indivisib…
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10. a chemical is a substance that is not natural. * 1 point true false
B. False
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4. how many points on your license will cause you to have to enroll and…
4. B. 8 5. (Answers vary by region, no specific answer provided here) 6. (Answers vary by region, no specific answer provided here) 7. Legally intoxicated 8. Zero - tolerance law …
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3. for each of the following statements, say whether the statement is t…
# Explications succinctes: a) Un molécule est formée par l'association de deux ou plusieurs atomes. Dans le cas de $N_2$, il s'agit de deux atomes d'azote liés, donc c'est une mol…
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which option is an example of a chemical property? ability to decompose…
ability to decompose
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10. a chemical is a substance that is not natural. * true false
False
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which option is an example of a chemical property? o density o rusting …
rusting ability
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which option is an example of a physical property? flammability reactiv…
solubility
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which option is an example of a physical property? ○ ph ○ boiling point…
boiling point
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details no additional details were added for this assignment. which pro…
chemical properties
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part b read each scenario. decide whether a physical or chemical change…
1. Physical change. Evidence: No new substances formed, just change in shape and state of bread. 2. Chemical change. Evidence: Burning produces char and smoke, new substances are …
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part c: true (t) or false (f) 1. changing the size and shapes of pieces…
1. F 2. F 3. T 4. T 5. F 6. F 7. T 8. F 9. F 10. F
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look at the text below. if there is an error with subject - verb agreem…
Fish and young corals can discern healthy reefs from fragile ones. Each of these creatures is able to detect chemical signals that help determine whether a reef is flourishing.
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can you recognize the chemical and physical changes that happen all aro…
1. P 2. C 3. C 4. P 5. C 6. C 7. P 8. P 9. C 10. P
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match each electron - configuration notation to the neutral element it …
Hydrogen (H) - $1s^1$ Oxygen (O) - $1s^22s^22p^4$ Sodium (Na) - $[Ne]3s^1$ Bromine (Br) - $[Ar]4s^23d^{10}4p^5$
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physical change 1. a change in size, shape, or state 2. no new substanc…
1. P 2. C 3. P 4. P 5. C 6. C 7. P 8. C 9. P 10. C 11. C 12. C 13. C 14. P 15. C 16. P
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conclusion: using the mass numbers you determined in your analysis of c…
The determined atomic mass makes sense because it is a weighted average of the mass - numbers of the isotopes, with the weights being the percent abundances of the isotopes. Isoto…
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name ______key physical property 1. observed with senses 2. determined …
1. P 2. P 3. C 4. P 5. C 6. C 7. P 8. P 9. C 10. P 11. P 12. P 13. P 14. C
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5. base your answer to the following questions on the data table below,…
a) The number of neutrons is different in the three isotopes of neon. b) $(19.99\times0.909)+(20.99\times0.003)+(21.99\times0.088)$
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chemistry worksheet name: elements, compounds & mixtures instructions 1…
1. Compound 2. Mixture of Elements 3. Mixture of Compounds 4. Mixture of Compounds 5. Element 6. Compound 7. A mix of Elements and Compounds 8. A mix of Elements and Compounds 9. …
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use the periodic table in the tools bar to answer the following questio…
What elemental classification does oxygen belong to? nonmetal What is the boiling point of gold? 2970°C What is silicon used for? Semiconductor devices in electronics
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station 1 understanding the periodic table which of the following lists…
B. C, Al, P, Cl
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use the periodic table to select the element that best fits each of the…
- Which element below is least reactive? Iodine (assuming no noble gases are in the list) - Which element below must be stored in oil because of its reactivity? Calcium
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answer each question about the following atom when it becomes an ion. c…
Ionic name: Chloride ion Chemical symbol and charge: $Cl^-$ The ionic charge of - 1 is achieved when the atom gains 1 electron.
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when two elements bond and form a compound, what happens to their elect…
They share or give away their electrons.
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question 9. which of the following symbols does not match the element n…
Mg, manganese
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protons: neutrons: electrons: what is the mass number? 0
2
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protons: 5 neutrons: 5 electrons: 5 what is the mass number? 0
10
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stion 8. use the periodic table to complete ollowing table with the mis…
| Element Name | Element Symbol | | ---- | ---- | | Mercury | Hg | | Strontium | Sr |
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question 7. in the modern periodic table, elements are arranged in orde…
atomic number
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question 6. the horizontal rows are called. there are in the periodic t…
The horizontal rows are called periods. There are 7 periods in the periodic table.
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protons: neutrons: electrons: find the element: is it: neutral atom ion
The element is Hydrogen (H). It is an ion.
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question 5. elements labeled with “a” are referred to as elements becau…
A. transition
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question 4. elements within a group have chemical and physical properti…
similar
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question 3. the vertical columns of the periodic table are called
Groups
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question 2. the letter of an element symbol is a letter , while the let…
first; capital; second; lowercase
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4. the compounds below give a purple color with iron(iii) chloride solu…
The circled parts in the provided structures are the phenolic - OH groups (the - OH groups directly attached to the aromatic rings) as they are responsible for the purple - color …
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question 1. the is an arrangement of elements in which the elements are…
D. periodic table
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osmium has a density of 22.6 g/ml. what volume, in ml, would be occupie…
54.4248
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question 23 1 point how many oxygen atoms are in 85.0 milligrams of caf…
D. 5.28E20 atoms
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13.) there are 88 naturally occurring elements and from those naturally…
There are more minerals than naturally - occurring elements because different combinations and arrangements of the 88 naturally - occurring elements under various geological condi…
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question 22 1 point there is typically a 0.15 mg dose of epinephrine in…
A. 4.9E17 molecules
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question 21 1 point your average cup coffee contains 1.15e2 mg of caffe…
C. 5.93E-4 moles
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calculate the percentage by mass, of carbon in albuterol, c₁₃h₂₁no₃. gi…
A. 65.3%
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question 4 of 16 > methyl isocyanate, shown as resonance structure 1, c…
Resonance structure 2: $H_3C - N^-=C=O^+$; For resonance structure 1, curved arrow from oxygen lone - pair to C - O to form double bond and from C - N double bond to N. For resona…
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les iroquoiens ont une organisation politique élaborée. choisissez, dan…
Clan : Chef de clan Village : Élus Nation : Sachems Confédération : Sachems des nations
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8) valence electrons: using the periodic table, fill in the missing inf…
| Element Name | Element Symbol | Total # of Electrons | # of Valence Electrons | Gain/Lose Electrons? | Ionic Charge | Lewis Structure | | ---- | ---- | ---- | ---- | ---- | ----…
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7) identify the sections of the periodic table a) b) c) d) e)
a) Alkali metals b) Alkaline - earth metals c) Transition metals d) Halogens e) Noble gases
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identify the groups and periods on the periodic table below.
Groups are the vertical columns and periods are the horizontal rows on the periodic table.
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5) determine the following information from the atom symbols: protons? …
For $_{20}^{42}Ca$: Protons: 20 Electrons: 20 Neutrons: 22 Mass #: 42 Atomic #: 20 Charge: 0 Atom, ion, or isotope: Isotope For $_{12}^{24}Mg^{2+}$: Protons: 12 Electrons: 10 Neut…
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11. write a chemical formula that shows 3 molecules of water:
$3H_2O$
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4. fill in the missing information in the data table below. then, using…
For $_{20}^{42}Ca$: Protons: 20 Electrons: 20 Neutrons: 22 Mass #: 42 Atomic #: 20 Charge: 0 Atom, ion, or isotope: Isotope For $_{12}^{24}Mg^{2+}$: Protons: 12 Electrons: 10 Neut…
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10. use the chemical formula below to complete the missing information.…
# of molecules: 4 # of elements: 3 Name of element: Aluminum, # of atoms: 8 Name of element: Carbon, # of atoms: 12 Name of element: Oxygen, # of atoms: 36 Total # of atoms: 56 Th…
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who first used the word “atomos” to describe the smallest unit of a sub…
B. Democritus
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9) 3mgcl2 coefficient: ____________ subscript for mg: ____________ subs…
coefficient: 3 Subscript for Mg: 1 Subscript for Cl: 2
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daltons theory states that atoms are the smallest possible parts of ele…
rearrange and form new substances with new properties.
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4) fill in the missing information in the data table below. then, using…
| Element | Atomic Number | Mass Number | # of Protons | # of Neutrons | # of Electrons | Atom/Ion/Isotope | Atom Symbol | |---|---|---|---|---|---|---|---| | Potassium | 19 | 39 …
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an atoms emission of light with a specific amount of energy confirms th…
electrons emit and absorb energy based on their position around the nucleus.
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the scattering of a stream of positively charged particles when strikin…
The positive charge in an atom must be located in a dense central mass.
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atoms & the periodic table review 1 label each part of the atom 2 name …
1. Since the picture of the atom is not clear - labeled, I'll provide general answers for parts of an atom: - a) Nucleus (contains protons and neutrons). - b) Proton (positively -…
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8. in what family would each of these elements be classified? radium - …
Radium - 2, Iodine - 7, Cesium - 1, Barium - 2, Lead - 4, Bismuth - 5
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which scientist and atomic model are correctly matched? bohr - plum pud…
Schrödinger – electron cloud surrounds nucleus
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part c: balance each of the following equations following the procedure…
$4P + 5O_2=P_4O_{10}$ $2Mg+O_2 = 2MgO$ $2HgO=2Hg + O_2$ $2Al_2O_3 = 4Al+3O_2$ $BaCl_2 + H_2SO_4=BaSO_4 + 2HCl$
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12 multiple choice 0.1 points a buser poured some cleaner from its orig…
Label the working container with the chemical's common name.
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balancing equations practice part a: identify the following parts of ea…
For $H_2$: coefficient 1, sub - script of H is 2; for $2HCl$: coefficient 2, sub - script of H is 1 and Cl is 1; for $4O_2$: coefficient 4, sub - script of O is 2; for $CH_4$: coe…
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which elements had complete outer shells? give the name and symbol for …
1. Noble gases have complete outer - shells. Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn). They are in Group 18. 2. Alkali metals have one valence elec…
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what is a chemical equation? it’s how we describe chemical reactions, u…
1. 4 2. 3 3. 6 4. 2 5. 4 6. 6 7. Yes
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h₂co₃ → h₂o + co₂ • how many atoms of hydrogen are in the reactant (tot…
- How many atoms of Hydrogen are in the reactant (total)? 2 - How many atoms of Carbon are in the reactant (total)? 1 - How many atoms of Oxygen are in the reactant (total)? 3 - H…
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h₂co₃ → h₂o + co₂ • how many atoms of hydrogen are in the reactant (tot…
- How many atoms of Hydrogen are in the reactant (total)? 2 - How many atoms of Carbon are in the reactant (total)? 1 - How many atoms of Oxygen are in the reactant (total)? 3 - H…
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c₃h₈ + 5o₂ → 3co₂ + 4h₂o • how many atoms of carbon are in the reactant…
- How many atoms of Carbon are in the reactant (total)? 3 - How many atoms of Hydrogen are in the reactant (total)? 8 - How many molecules of $O_2$ are in the reactant? 5 - How ma…
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3. when silver nitrate and sodium iodide were mixed, a white precipitat…
The precipitate is silver iodide.
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match the scientists with the correct atomic models. ernest rutherford …
Ernest Rutherford - central nucleus with electrons that orbit at a distance J.J. Thomson - electrons mixed in a positive sphere, also called the plum pudding model Democritus and …
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part 3: independent work try balancing these more complex equations. sh…
1. C3H8+5O2→3CO2+4H2O 2. 2KClO3→2KCl+3O2 3. 3Ca(OH)2+2H3PO4→Ca3(PO4)2+6H2O
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22) omar is running a chemical reaction that can be modeled by a quadra…
Approximately 10.02 minutes
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whenever you reach a stop and jot question in the stemscopedia, stop an…
1. No. 2. Yes. An element has a single - atom chemical symbol, while a compound has a formula with multiple elements. 3. Elements have one type of atom; compounds have two or more…
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3. al+cl2→alcl3 work: answer: 4. n2+h2→nh3 work: answer:
3. $2Al + 3Cl_2=2AlCl_3$ 4. $N_2+3H_2 = 2NH_3$
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lattice energy is a measure of ionic - bond strength. the lattice energ…
Iodide ($I^-$)
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ionic crystals find use in the frequency manipulation of laser light. o…
Lithium ion
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the manufacture of many materials essential to engineering requires ver…
$BaO < CaO < MgO$ (lowest melting - highest melting)
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part 2: practice balance these equations. show your work (atom counts, …
1. $2H_2+O_2 ightarrow2H_2O$ 2. $4Fe + 3O_2 ightarrow2Fe_2O_3$
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the coulombic forces that hold the ions together in an ionic solid are …
Bromellite - $Ba^{2+}O^{2 - }$
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8. the story could be read as an allegory, a story in which people, obj…
| Character | What he or she loses/wastes | What happens when she/he is given a second youth | What he or she might represent | |--|--|--|--| | Mr. Medbourne | Wealth | Schemes to…
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the coulombic forces that hold the ions together in an ionic solid are …
$AlF_3$
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ionic solids are often water soluble, because the ions solvate very wel…
C (diamond), SiO₂, NiO
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ionic solids are often very strong materials, such as minerals and rock…
They have many positive and negative charged ions.
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ionic solids can be used to transport ions, since they are composed of …
The two atoms have very different electronegativities.
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2. do you think the property of magnetism is a physical property or a c…
4. Melting ice: Chemical composition remains same, only state changes. Tearing paper: Chemical makeup unchanged, physical form altered. Dissolving salt in water: Chemical identiti…
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4) draw the lewis dot diagram for the following elements. then draw the…
Lewis Dot Diagrams: - $Ca^{2+}$: No dots. - F: 7 dots around F. - $Li^{+}$: No dots. - N: 5 dots around N. Bohr Diagrams: - $Ca^{2+}$: 3 shells with 2, 8, 8 electrons. - F: 2 shel…
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balancing chemical equations assignment part 1: key concepts reactant p…
Reactant: A substance in a chemical reaction that changes. Product: A substance formed in a chemical reaction. Coefficient: A number before a chemical formula in a balanced equati…
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determine the mass in grams of 2.91 moles of licl
123
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daltons theory was identified using light microscope images of atoms. t…
water vapor and air experiments.
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stemscopedia: stop and jot whenever you reach a stop and jot question i…
1. Yes, a new substance is created when a cake is baked. 2. Magnetism is a physical property because it can be observed without changing the chemical identity of a substance. 3. P…
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hydrogen reacts with fluorine to produce hydrogen fluoride. the diagram…
b.