化學
化學反應、化學計量、分子結構與元素性質。
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some people mistakenly believe that the element curium was discovered b…
D. nuclear chemist Glenn T. Seaborg
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arrange the following newman projections of butane in order of energy.
IV<II<III<I
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76. which of the following are the same and which are different? a. a s…
a. Son lo mismo. b. Son diferentes. c. Son diferentes. d. Son lo mismo.
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multiple choice 2 points. name the alkane shown: 5 - ethyl - 2,2 - meth…
D. 5 - ethyl - 2,2 - dimethyloctane
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11 multiple answer 2 points which statements describe a sigma (σ) bond?…
- Occurs in all single covalent bonds - It is formed by end - to - end orbital overlap - Allows free rotation around the bond axis
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10 multiple answer 2 points which statements about triple bonds are cor…
A. Are generally shorter than double bonds B. Show sp hybridization on carbon D. Consist of one sigma and two pi bonds
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multiple choice 2 points what name is given to a hydrocarbon that conta…
D. aromatic
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6. explain the difference between extensive properties and intensive pr…
6. Extensive property: mass; Intensive property: density 7. Physical change: alteration of physical form without chemical change. Examples: melting ice, cutting paper 8. Solids: p…
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multiple choice 2 points which of the following has the highest boiling…
The compound with the -OH group (the third - option with the OH functional - group)
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the lewis structure of pentane is shown below. which of the following r…
D. $CH_3(CH_2)_3CH_3$
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multiple choice 2 points which line - angle formula corresponds to the …
IV
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determine which compound for the group below will be the least soluble …
C. Chlorocyclopentane will have the lowest solubility in water because it is the least polar of the three compounds.
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multiple choice 2 points which of the following condensed formulas repr…
CH₃CH₂CH₂OCH₂N(CH₂CH₂CH₃)₂
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determine which structure(s) correspond to a cis isomer.
In cis - isomers, identical groups are on the same side of the ring. Analyzing the given structures: - In structure (i), the two $NH_2$ groups are on the same - side of the ring, …
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provide the planar form of the chair conformation below. 54:40 time rem…
Without seeing the specific correct option among the ones provided in the image (as the image quality may not allow for clear identification of details), the general approach is t…
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75. “a mixture is the chemical bonding of two or more substances in any…
# Explicación breve: Una mezcla se forma por la simple combinación física de dos o más sustancias, sin que se produzca un enlace químico entre ellas. Las sustancias en una mezcla …
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1. what is the definition of chemistry? the study of the composition, s…
1. Chemistry is the study of the composition, structure, and properties of matter. 2. Organic, Inorganic, Physical, Analytical, Biochemistry, Theoretical. 3. Basic research is for…
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60. is it possible to distinguish between an element and a compound? ex…
# Explicaciones Breves: Un elemento está formado por un solo tipo de átomo y no puede descomponerse en sustancias más simples por métodos químicos normales. Un compuesto está form…
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14. which statement concerning ⁷⁹₃₄ se and ⁷⁹₃₅ br is true? a. ⁷⁹₃₄ se …
B. $^{79}_{34}Se$ has more neutrons per atom than $^{79}_{35}Br$.
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match each of the following as a physical or chemical change. answers w…
milk turns sour: Chemical change butter solidifies: Physical change wood is burned: Chemical change food is digested: Chemical change coffee beans are ground: Physical change ice …
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56. state the definition of element. 57. correct the following statemen…
56. Un elemento es una sustancia pura formada por un solo tipo de átomo que no puede ser descompuesta en sustancias más simples por medios químicos normales. 57.a. Un elemento es …
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graded formative: unit 1 study guide part 1 classify each substance bel…
Propanol (C₃H₇OH): compound Xenon (Xe): element Kool-Aid drink solution: homogeneous mixture oil & vinegar: heterogeneous mixture
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57. correct the following statements. a. an element is a combination of…
a. Un elemento es la forma más simple de materia que no puede descomponerse en otras sustancias químicas más simples por métodos químicos comunes. b. Cuando un pequeño monto de az…
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format and style quick check \why shade balls may not save water\ by am…
by inserting a heading about the topic of the second section
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whats the difference between an acid and a base?
Acids release hydrogen ions in solution, taste sour, and react with bases. Bases release hydroxide ions or accept hydrogen ions, taste bitter, feel slippery, and have different in…
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graded formative: unit 1 study guide part 1 jane calculated the density…
accurate and precise
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31. list three examples of substances. explain why each is a substance.
1. Agua (H₂O): Compuesto formado por oxígeno e hidrógeno en proporción fija. 2. Oxígeno (O₂): Elemento, átomos de oxígeno, no descomponible químicamente. 3. Hierro (Fe): Elemento,…
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question 2. during a chemical reaction, if 25 grams of reactants are co…
The law of conservation of mass is upheld because the mass of the products equals the mass of the reactants.
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approximately how many elements are there in the modern table? a 20 b 5…
C. 100
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who invented the periodic table? a albert einstein b august kekulé c ch…
D. Dmitri Mendeleev
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question 1. a pure white, solid material that looks like table salt rel…
A chemical change occurred because the material released gas when heated, which indicates a change in its chemical reactivity and composition.
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which statement best describes the arrangement of electrons in an atom …
There are two electrons in the first energy level and seven electrons in the second energy level.
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which element has atoms with valence electrons in a higher energy level…
A. Strontium (Sr)
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helium is in group 18 of the periodic table. how is helium different fr…
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
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two representative elements, nitrogen and oxygen, are in the same perio…
They have valence electrons in the same energy level.
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how many valence electrons does each atom of arsenic (as) have? arsenic…
5
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q8. how many liters of a 25% sulfuric acid solution should be mixed wit…
5
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calculate the volume of a solvent from a solution that has a density of…
$0.206$ L
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instructions: using the diagram below as a reference, fill in the missi…
The above diagram shows what happens as heat is applied to a substance. Beginning at point A on the timeline, the material is a solid and has a definite volume and a definite **sh…
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assignment #4 quiz (a4 - 1 point) why does oil not dissolve in water? w…
Water is polar and oil is nonpolar so hydrogen bonds cannot form between water and oil.
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assignment #4 quiz (a4 - 1 point) water is a molecule because the oxyge…
Polar
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(a4 - 2 points) drag and drop the correct answer in each box to complet…
1. Acids 2. Bases
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1 - 5 density the concept of density is about how close atoms and molec…
1. 9; 9 2. 2 3. 1 4. 2 5. mass 6. volume
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what is matter? mention one example of matter and say if you think is p…
Matter is anything that occupies space and has mass. An example of matter is water. Pure water consists only of H₂O molecules. But natural - water like river water is not pure as …
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6. the author uses the statement \these technological marvels seem like…
6. G. consumers regard many technological inventions as unremarkable. 7. D. our current pattern of lifestyles and consumer habits.
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a 52 - kg woman has 7.2×10⁻³ mol of hemoglobin (molar mass = 64456 g/mo…
$4.3\times 10^{41}$ molecules of hemoglobin (rounded to 2 significant - figures as 7.2 has 2 significant - figures)
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1 st alice tente didentifier un sucre inconnu qui est soluble dans leau…
#### a) On a calculé que la concentration du sucre inconnu en solution saturée est inférieure à ce que devrait être la solubilité du saccharose à $22^{\circ}C$ en utilisant le gra…
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lesson 2.2 review 1. what does it mean when a molecule is said to be “p…
1. Uneven charge distribution. 2. It's polar and forms hydrogen - bonds. 3. A substance resisting pH change; maintains cellular pH.
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5. describe two observations of water that provide evidence that water …
1. Water forms droplets. 2. Water has high surface - tension (e.g., insects can walk on it).
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1 indique si chacun des énoncés est vrai ou faux. sil est faux, corrige…
a) Vrai b) Faux. L'observation des propriétés chimiques d'une substance implique généralement des réactions chimiques qui modifient la nature de la substance. c) Faux. La liqueur …
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reading check (page 48) how are cohesion and adhesion similar? how are …
Similarity: Both are intermolecular attractions. Difference: Cohesion is like - molecule, adhesion is unlike - molecule. Solvent in tea: Water. Solute in tea: Tea compounds.
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reading check (page 45): how are ionic and covalent bonds alike? how ar…
1. Protons and neutrons in nucleus, electrons in energy - levels around it. Diagram with labeled parts. 2. Same number of protons means same electron configuration and chemical be…
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lesson 2.4 review 1. what changes occur to chemical bonds during a chem…
1. Chemical bonds break and new ones form. 2. Exergonic (negative - energy change) reactions are likely to occur. 3. Enzymes catalyze reactions in living things by lowering activa…
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4. osha was created as part of the u.s. department of labor (dol) to en…
5. To ensure that employers and employees understand the physical and health hazards of chemicals in the workplace. 6. They protect my health by making me aware of and able to man…
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methods of expressing concentration of a solution g. normality (n) find…
- 0.15 M HCl: 0.15 N - 1.4 M H₂SO₄: 2.8 N - 2 M NaOH: 2 N - 0.4 M Ba(OH)₂: 0.8 N
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1 multiple choice 1 point which of the following best describes a hydro…
1. Water is used to break a bond 2. An amino acid
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which of the following correctly pairs the substance with its ph range?…
1. D. Stomach acid - pH 1 - 2 2. D. Ionic bonds
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q2(in class quiz) 1 multiple choice 1 point which of the following best…
Water is used to break a bond
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imagine you work at the front desk of a local clinic. you arrive early …
A. Look up the storage information for the chemical in the products' MSDS.
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maggie works in a hospital and came into contact with some chemicals th…
B. No, Maggie's supervisor is legally not allowed to have any conversations with Maggie's doctor.
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hormones are chemicals secreted and regulated by the endocrine system. …
T
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7. alicias cheapskate boyfriend gave her a ring he claims is 24 carat g…
For the ring problem: Volume of ring: 1.5 mL Density of ring: approximately 10.19 g/mL. She should throw it at him as the density is much lower than that of 24 - carat gold. For t…
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the plot in the tb - plane shows the brewing time, b, defined as the ti…
B. \(B = 9\cdot0.96^{T}\)
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the biogeochemical cycles the water cycle 1. what are the major reservo…
1. Oceans, ice caps and glaciers, groundwater, surface water (lakes, rivers), atmosphere. 2. In arid regions, lack of precipitation; human - induced disruptions. 3. Reforestation,…
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physical property 1. observed with senses 2. determined without destroy…
The answers in the image are correct as per the definitions of physical and chemical properties and changes. For the first part: 1. P 2. P 3. C 4. P 5. C 6. C 7. P 8. P 9. C 10. P…
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the rate of a certain reaction is given by the following rate law: rate…
k = 271.4 $M^{-3}s^{-1}$ If $N_2$ concentration is doubled, rate changes by a factor of 8 Overall reaction order: 4 Reaction order in $O_3$: 1 Reaction order in $N_2$: 3
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food color is dropped into water to give it color. chewing food to brea…
1. F 2. F 3. T 4. T 5. F 6. F 7. T 8. F 9. F 10. F
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consider the following 3 sets of protons and electrons. which set has t…
C
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part b read each scenario. decide whether a physical or chemical change…
1. Physical change; No new substances formed. 2. Chemical change; New substances (charred bread, smoke) formed. 3. Chemical change; Rust (new substance) formed. 4. Physical change…
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part a physical and chemical changes can you recognize the chemical and…
1. P 2. C 3. C 4. P 5. C 6. C 7. P 8. P 9. C 10. P
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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. P 9. C 10. P 11. C 12. C 13. C 14. P 15. C 16. P
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name key physical property 1. observed with senses 2. determined withou…
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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3. an unknown compound, believed to be a hydrocarbon, showed the follow…
The compound is the benzene ring (the third structure in the given list)
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2. a student has two compounds in two separate bottles but with no labe…
a. Octane: Insoluble; 1 - Hexene: Insoluble b. Octane: Soluble; 1 - Hexene: Soluble c. Octane: Burns with a clean flame; 1 - Hexene: Burns with a smokier flame d. Octane: Less den…
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d. + kmno₄ (aq) →
No reaction occurs.
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11) complete the following table to describe three states of matter. th…
| | Solid | Liquid | Gas | |--|--|--|--| | Shape | Fixed | Not fixed, takes the shape of the container | Not fixed, fills the container | | Volume | Fixed volume | Fixed volume | …
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33. a volume of 5.00 ml of mercury is added to a beaker that has a mass…
$155.3\ g$ ### 40.
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please fill in the missing information with regards to the description …
| Description | Noble Gas Core Electron Configuration of the Neutral Atom | Chemical Symbol of the Metal | Name of the Metal | |--|--|--|--| | A metal ion with a net charge of + 4…
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name: date: per: chemistry lab equipment crossword across 2 a long non …
(As the actual crossword filling requires visual interaction and cannot be fully presented in text - only format here, it's best to solve it on the actual paper. But here are some…
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for the group of four atoms or ions provided below, please select the s…
As³⁻, Se²⁻, Br⁻, Kr
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1. below are four organic compounds. the reagent shown is added to the …
a. Product: $CH_3CHBrCH_2Br$, Observation: Red - brown color of $Br_2$ disappears b. Product: Cyclohexane - 1,2 - diol, Observation: Purple color of $KMnO_4$ fades c. Product: $CH…
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write the ground - state electron configurations of the following trans…
Part 1 of 4: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{5}$ Part 2 of 4: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}$ Part 3 of 4: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{7}$
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write the ground - state electron configuration for the following ion, …
$1s^{2}2s^{2}2p^{6}$
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please fill in the missing information with regards to the description …
Noble Gas Core Electron Configuration of the Neutral Atom: $[Ar]3d^{5}4s^{2}$; Chemical Symbol of the Metal: Mn; Name of the Metal: Manganese
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a m²⁺ ion has two electrons in the 3d subshell and is derived from a me…
Cr
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which group of the periodic table is the following element found in? ne…
Group 14
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which of the following electron configurations represents an element wi…
$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}$
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for the electronic configuration given, choose the electronic configura…
$1s^{2}2s^{2}2p^{6}3s^{2}3p^{3}$
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chemical changes anthony is performing an experiment. he adds 0.25 gram…
5.25 grams
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a science teacher demonstrated physical and chemical changes by using a…
- The marshmallow changes shape: Physical (P) - The wick turns black: Chemical (C) - The marshmallow burns: Chemical (C) - The candle releases smoke: Chemical (C) - The fork is ho…
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a science teacher demonstrated physical and chemical changes by using a…
the marshmallow changes shape: P the wick turns black: C the marshmallow burns: C the candle releases smoke: C the fork is hot: P the wax melts: P
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write the ground - state electron configurations of the following trans…
Part 1 of 4: $Pd^{2+}$ has ground - state electron configuration $[Kr]4d^{8}$ Part 2 of 4: $Sc^{3+}$ has ground - state electron configuration $[Ar]$
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what does an abrupt change from blue to yellowish - green in bromothymo…
increased CO₂ levels
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which group of the periodic table is the following element found in? ar…
Group 4
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which of the following best describes the relationship between co₂ prod…
$CO_2$ production results in a yellowish - green color.
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what role did the resting rate play in the bromothymol blue experiment?…
a control
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assignment multiple - choice question what is called when a solid chang…
sublimation
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what type of assessment does the observable color change in the bromoth…
B. qualitative
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12 which of these describes effusion? a gas that closely follows kineti…
12. The movement of gas particles through a small hole 13. Force applied per unit area 14. Solid
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multiple - choice question what is a melting_point? the temperature at …
the temperature at which a solid becomes a liquid