Chemie
Chemische Reaktionen, Stöchiometrie, Molekülstrukturen und Elementeigenschaften.
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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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17 quelle est la masse de chacun des échantillons suivants? a) 0,25 mol…
b) $336,59\ g$ c) $98,07\ g$ d) $854,395\ g$
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1. what element is located in a. group 2, period 5? b. group 16, period…
1a. Strontium (Sr) 1b. Selenium (Se) 1c. Boron (B) 1d. Niobium (Nb) 2. Francium (France), Germanium (Germany), Polonium (Poland) 3. Curium (Marie and Pierre Curie), Einsteinium (A…
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part e - critical thinking 21. a cold pack becomes icy after being sque…
21. Endothermic. Heat is absorbed as the pack becomes cold. 22. Sink. Density of aluminum is $2.7\ g/cm^{3}$ which is greater than water's density of $1\ g/cm^{3}$. 23. Synthesis …
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24. a rock dropped in a graduated cylinder raises the level of water fr…
$3\mathrm{g/cm}^3$
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part d - balancing practice balance each equation: 16. h₂ + cl₂ → hcl 1…
16. $H_2+Cl_2 = 2HCl$ 17. $4K + O_2=2K_2O$ 18. $CaCO_3 = CaO+CO_2$ 19. $Zn + 2HCl=ZnCl_2 + H_2$ 20. $2C_2H_6 + 7O_2=4CO_2+6H_2O$
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daily activator: periodic table practice 1. tell which element is locat…
1. a. Hydrogen b. Zirconium c. Beryllium d. Tungsten e. None f. Tin g. Zinc h. Francium i. Polonium j. Chlorine k. Silver l. Vanadium m. Platinum n. Aluminum 2. a. NM b. M c. M d.…
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exprime chacune des quantités suivantes en moles. a) 32 g de carbone. b…
a. $\frac{8}{3}\ mol\approx2.67\ mol$ b. $\approx12.69\ mol$ c. $\approx1.99\ mol$ d. $\approx0.88\ mol$ Oui, ils ont raison.
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5. what does \endothermic\ mean in terms of energy flow?
An endothermic process means the system absorbs energy (usually heat) from the surroundings.
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4. define neutralization reaction and give a real - life example.
A neutralization reaction is a chemical reaction between an acid and a base to form a salt and water. A real - life example is the use of antacids to neutralize stomach acid.
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14 - 18. list the substances a - e in order from most dense to least de…
Substance B, Substance A, Substance E, Substance D, Substance C
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part b - multiple choice 6. which subatomic particle determines the ide…
6. a) Proton 7. c) Neon (Ne) 8. c) Produces OH⁻ ions in solution 9. b) N₂ + 3H₂ → 2NH₃ 10. b) Melting ice
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16 combien y a - t - il datomes dans 19,0 mol deau (h2o)? réponse: 17 q…
1. **Question 16: Calcul du nombre d'atomes dans 19,0 mol d'eau ($H_2O$)** - # Explanation: - ## Step1: Savoir le nombre d'atomes par molécule d'eau - Une molécule d'eau ($H_2O$) …
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une technicienne spécialiste de la qualité de lair a détecté 0,020 mg d…
La quantité de contaminants détectée ne présente pas de danger pour la santé humaine.
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4. strontium consists of four isotopes with masses of 84 (abundance 0.5…
87.712
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3. naturally occurring europium (eu) consists of two isotopes was a mas…
$152.04$
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when solid ice cream becomes a liquid, what happens to the particles? t…
The particles gain energy and move faster.
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2. complete the following chart: isotope name atomic # mass # # of prot…
| Isotope name | atomic # | mass # | # of protons | # of neutrons | # of electrons | | ---- | ---- | ---- | ---- | ---- | ---- | | 92 uranium - 235 | 92 | 235 | 92 | 143 | 92 | | …
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refer to the illustration. molecules like molecule 1 are found in * 0/1…
D. carbohydrates
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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
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who was the scientist who proposed the plum pudding model? thomson dalt…
A. Thomson
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who was the scientist who proposed that the atom is a solid sphere of m…
A. Dalton
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how do you calculate the mass number of an atom? mass number = # neutro…
B. Mass number = # protons + # neutrons
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3. describe what type of electron transfer happens between these two at…
An ionic electron transfer occurs where magnesium donates 2 electrons to oxygen.
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2. which ion could bond with a calcium ion (ca²⁺) to form a neutral ion…
C. $S^{2 - }$
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1. when a neutral atom either loses or gains an electron, it becomes el…
A. ion
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what is the name of a row on the periodic table? a period a group a set…
A. A period
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you can make a solution more dilute or more concentrated by changing th…
1. more concentrated 2. more dilute 3. more concentrated 4. more dilute 5. more concentrated 6. more concentrated 7. more dilute
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drag and drop each term to the correct blank to complete the prompt. it…
Water is the solvent. The lemonade - mix is the solute. As the ice melted, the lemonade became more dilute. If you want the lemonade to be more concentrated, you could add another…
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your mom asked you to make a pitcher of sweet tea. what can you do to h…
1. Use the granulated sugar 2. Add sugar to tea while it is hot 3. Stir the tea vigorously
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2. baking powder and baking soda can lose their freshness and not work …
For baking powder, add 1 teaspoon to 1/2 cup warm water and check for vigorous fizzing. For baking soda, mix 1/4 teaspoon with a few drops of vinegar and look for strong fizzing.
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you poured a soda into your cup and remembered from your science class …
Solute: Flavorings, sugar, carbon dioxide, caffeine Solvent: water
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1. some powders should have given off gas bubbles upon reaction with vi…
D. $CO_2$
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classify each action as something that speeds up the rate at which solu…
Speeds up rate: stirring, heating, use smaller solute particles, crushing solute Slows down rate: cooling, use larger solute particles
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youre making fresh - squeezed lemonade with your grandmother. sort each…
Solute: sugar, yellow food coloring Solvent: lemon juice, water
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multiple - choice question what is/are the correct unit(s) for average …
atomic mass units
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element x has three stable isotopes. x - 12 has 80% abundance. x - 13 h…
15.01
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4. many fish and aquatic plants can survive a cold winter because a lay…
B. Water expands and becomes less dense when it freezes.
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complete the text with the analysis that most logically connects the cl…
The researchers attributed much of the success of their project to the efficiency and breadth of the citizen scientists’ work.
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a) a block of aluminum occupies a volume of 15.0 ml and mass of 40.5 gr…
$2.7$ g/mL
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adapted from presidential retreat by the national parks service camp da…
The underlined sentence is: a piece of relevant supporting evidence It connects ideas in the text by: providing a specific example to support the argument
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to rent a certain meeting room, a college charges a reservation fee of …
$t\leqslant7$
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multiple select question select all that apply which two statements des…
- The atoms of the reactants are rearranged to form the products. - The products and reactants must weigh the same.
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which compound can be oxidized to a carboxylic acid
The third compound (the straight - chain alcohol with -OH at the end)
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to rent a certain meeting room, a college charges a reservation fee of …
$r\leq7$
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8. describe the difference between a heterogeneous and homogeneous mixt…
A homogeneous mixture is uniform throughout and components are indistinguishable visually. A heterogeneous mixture is non - uniform and components are distinguishable or separable.
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nfpa 70e primarily aims to establish a safe working area for employees …
A. Electricity
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homework - due in class 9/18 (thursday) classifying matter - classify t…
6. Homogeneous 7. Heterogeneous 9. c. Are arranged in a regular geometric pattern 10. Draw separate H₂O molecules with hydrogen atoms (lightly shaded) and oxygen atoms (darker sha…
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bottles, cans, and plastics are ____________. biodegradable pollutants …
C. non - biodegradable pollutants
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which of the following is not a factor in determining the severity of a…
B. Color
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part 3a 12 marks choose 4 of 5 (lesson 3a) draw the following ionic bon…
a) Formula: $Li_3P$ b) Formula: $CaCl_2$ c) Formula: $Mg_3N_2$ d) Formula: $AlCl_3$ e) Formula: $KBr$
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in 1974, mexican chemist mario molina and us chemist f. sherwood rowlan…
B. Specifically
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question 8 a firefly uses specialized muscles to draw oxygen into its l…
B. By contrast
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while researching a topic, a student has taken the following notes: • m…
C. Cosmochemist Kentaro Terada set out to determine whether some of the Moon's oxygen was coming from Earth.
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10. ice melting is an example of a(n) ________ process. (1 point) endot…
A. endotérmico
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8. a process that absorbs energy from its surroundings, usually in the …
# Breve explicación: Un proceso endotérmico absorbe energía del entorno, generalmente en forma de calor. Un proceso exotérmico libera energía. La energía cinética se asocia con el…
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7. the amount of energy required to break a chemical bond is called kin…
# Breve explicación: La energía necesaria para romper un enlace químico se conoce como energía de enlace. La energía cinética se asocia con el movimiento de partículas, la energía…
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5. a process that releases energy to its surroundings, usually in the f…
# Breve explicación: Un proceso exotérmico libera energía al entorno, generalmente en forma de calor. Un proceso endotérmico absorbe energía. La energía cinética se asocia con el …