化学
化学反应、化学计量、分子结构与元素性质。
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what is the main goal of secondary treatment in sewage treatment plants…
to remove organic waste using microorganisms
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in the reaction of silver nitrate solution, which is colorless, with co…
A. copper nitrate
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what coefficient is placed in front of o2 to complete the balancing of …
A. D) 7
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2 what are the products? cuco3(s)→cuo(s)+co2(g) 123.6 g 79.6 g + 44.0 g…
The products of the decomposition of $\mathrm{CuCO_3}(s)$ are $\mathrm{CuO}(s)$ and $\mathrm{CO_2}(g)$ which is consistent with the given reaction and mass - values. For the quest…
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use the passage from \the lady, or the tiger?\ to answer the question. …
By contrasting the terrifying nature of the tiger with the beauty of the lady through visual imagery
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missed this? watch kcv: writing and balancing chemical equations, iwe: …
$Se(s)+2O_2(g)+H_2O(l)=H_2SeO_4(aq)$
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magnesium hydroxide, the active ingredient in milk of magnesia, neutral…
$4.08\ g$
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question 7 1 pts cigarette smoke contains a variety of poisons, and has…
D. 4,000
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which two particles are found in the nucleus of an atom? protons and ne…
# Breve explicación: Los átomos están compuestos por un núcleo y electrones en orbitas alrededor del núcleo. El núcleo está formado por protones, partículas cargadas positivamente…
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question 8 1 pts something that causes cancer is known as a carcinogen …
Question 8: A. carcinogen Question 9: C. cancer and heart disease
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which of the following is the addictive substance in a cigarette? tar n…
Question 1: B. nicotine Question 5: D. because they contain nicotine Question 6: A. tar
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how are isotopes defined? forms of different elements that have the sam…
forms of the same element that differ in the number of neutrons in each atom
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the mass number of a chromium atom is 52 and it has 24 protons. how man…
28
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an atom of element be has four protons, four electrons, and five neutro…
# Explicación: ## Paso 1: Recordar la definición de isótopo Los isótopos son átomos del mismo elemento que tienen el mismo número de protones pero diferente número de neutrones. E…
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carbon - 12 and carbon - 13 are isotopes of carbon. which statement is …
# Explicaciones Breves: Los isótopos son átomos del mismo elemento químico que tienen el mismo número atómico (igual número de protones), pero diferentes números de masa (distinto…
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ammonia can also be synthesized by the reaction: 3h₂(g) + n₂(g) → 2nh₃(…
$29.4$
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the structure of the atom build an atom what is the biggest atom that c…
neon
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ic 25 - 26 physical science 1 the structure of the atom build an atom a…
# Explicación: ## Paso 1: Comprender los conceptos básicos El número de protones determina el elemento químico. Aquí, todos los átomos tienen 3 protones, lo que significa que son …
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the structure of the atom build an atom click the reset button (curved …
El átomo representa flúor (F), que es neutro eléctricamente cuando tiene un número igual de protones, neutrones y electrones. Agregar 1 neutrón y 1 electrón lo convierte en un ión…
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2.1 - i can explain how ions are formed and determine the ionic charge …
1. neutral 2. negative 3. a. 5; b. 13 4. b. Kr, c. $Se^{2 -}$, e. $Sr^{2+}$ 5. Calcium ion: Protons = 20, Total electrons = 18, Charge = + 2, Number of $e^-$ lost = 2, Cation; Nit…
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the structure of the atom build an atom use the neutral atom that you m…
# Explicación paso a paso: ## Paso 1: Comprender los conceptos básicos Un átomo neutro tiene igual número de protones y electrones. Al remover electrones, se crea una carga neta. …
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ic 25 - 26 physical science 1 the structure of the atom build an atom a…
El modelo atómico representa litio (Li). Su número atómico es 3 y está determinado por el número de protones. Su masa atómica es determinada por el total número de protones y neut…
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boron has an average atomic mass of 10.81. one isotope of boron has a m…
11.01
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practice calculating average atomic mass strontium isotope mass (amu) a…
# Explicación: ## Paso1: Convertir abundancias a fracciones decimales $0.56\% = 0.0056$, $9.86\%=0.0986$, $7.00\% = 0.07$, $82.58\%=0.8258$ ## Paso2: Calcular el producto de masa …
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practice calculating average atomic mass using the information in the t…
# Explicación: ## Paso 1: Convertir abundancias a fracciones decimales $69.17\% = 0.6917$ y $30.83\%=0.3083$ ## Paso 2: Multiplicar masa de cada isótopo por su fracción decimal de…
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practice calculating average atomic mass using the information in the t…
$63.45$ amu
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periodic table scavenger hunt instructions: use the periodic table to a…
1. 8 2. Approximately 35.45 3. Au 4. Potassium 5. Helium 6. 26 7. Neon 8. 6
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chlorine has an atomic number of 17. how many neutrons are present in a…
18 (corresponding to the fourth option)
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if you think of the plum pudding model as \the chocolate chip cookie do…
D. Negatively charged electrons
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what subatomic particle has a mass of 1/2,000 amu? the alpha particle t…
C. The electron
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what is the symbol for a proton? p- p pr p+
D. $p^{+}$
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if potassiums atomic mass is 39.10 amu and its atomic number is 19, how…
D. 20
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what is the mass of an atom that has 20 protons, 21 neutrons, and 20 el…
B. 41 amu
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what is the symbol for an electron? ele e e+ e-
D. e⁻
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galliums atomic mass is 69.72 amu, what isotope of gallium is most like…
Gallium - 69
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complete the analogy. atom is to molecule as letter is to spell chemica…
D. word
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which subatomic particle is found in the nucleus of an atom? neutrons p…
C. Both of these
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what is the current model of the atom? the electron cloud model the pla…
A. The electron cloud model
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what are isotopes? atoms of the same element but with a different mass …
Atoms of the same element but with a different mass
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what subatomic particle determines the identity of the element? the ele…
B. The proton
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grade 10 science: diagnostic test answer the following questions in the…
1. Workplace Hazardous Materials Information System 2. Hazardous Household Product Symbol 3. chemical; reactants 4. element 5. Metals 6. nucleus 7. b. A car rusts. 8. a. atomic nu…
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question 6 2 pts the effectiveness of various metals in preventing rust…
The one iron nail.
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question 3 (1 point) what properties describe what happens when a subst…
C. Chemical properties
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question 7 (1 point) when the drug heroin comes into contact with the m…
C. It turns purple
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question 3 (1 point) which of the following is/are a reactant in the ch…
Question 3: c. $\mathrm{C_6H_{12}O_6}$, d. $\mathrm{O_2}$ Question 4: a. $\mathrm{H_2O}$, b. $\mathrm{CO_2}$
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12. if you are asked to calculate percent error, you should know that p…
12. Approximately 15.4% 13. 1000, 1000, 273.15 14. 3, 5, 3, 1, 4, 2, 2 15. 0.77 g/mL 16. 85.2
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electron density model of h₂o 1. how many hydrogen atoms are in a molec…
1. 2 2. 1
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aspirin is a medicine used to treat pain, fever, and other conditions. …
- Each hydrogen atom forms 1 covalent bond(s) and has 0 lone pair(s). - Each carbon atom forms 4 covalent bond(s) and has 0 lone pair(s). - Each oxygen atom forms 2 covalent bond(…
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which of the following is the best example of a compulsion? a. will can…
C. Jordy locks his door exactly nine times every time he leaves the house to make sure it is locked.
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q.9. an atom has 23 protons and 24 neutrons. which of the following is …
d) Protons= 23, mass number= 52
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vitamin c (ascorbic acid) is an essential nutrient and antioxidant. it …
A. single bond
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1. how many hydrogen atoms are in a molecule of water? 2. how many oxyg…
# Explicación: ## Paso 1: Identificar átomos de hidrógeno en agua La fórmula química del agua es H₂O, lo que significa que hay 2 átomos de hidrógeno. ## Paso 2: Identificar átomos…
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7. now match the separation technique with the picture: chromatography …
Flush the affected area with large amounts of water immediately. ### 10.
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atomic theory (fill in the blank) give name of scientist and name of mo…
1. A. $(35\times0.75)+(37\times0.25)$ 2. J. is mostly empty space. 3. C. two more neutrons. 4. J. 18 5. C. $13e^-,13p^+$, and $14n$ 6. J. $1s^22s^22p^63s^23p^64s^2$
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video discussion guide questions. 1. what is an atom? 2. what are the p…
1. The smallest unit of ordinary matter that forms a chemical element. 2. Protons, neutrons, and electrons. 3. Groups of two or more atoms held together by chemical bonds. 4. Hydr…
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____ is an inorganic nutrient that the body usually needs in small amou…
C. A mineral
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____ is an inorganic nutrient that the body usually needs in small amou…
C. A mineral
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question 10 (1 point) saved a molecule exhibits the trigonal planar sha…
Three
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bromine, a liquid at room temperature, has a boiling point of 58 °c and…
pure substance.
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question 11 (1 point) the bond angle in co3 2- is expected to be approx…
C. 120 degrees
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elements, compounds, and mixtures a teacher makes this statement. \gaso…
distillation of a mixture
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for each nonmetal below, identify how many covalent bonds (shared elect…
H: 1 C: 4 N: 3 O: 2 Cl: 1
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question 12 (1 point) a molecule exhibits the trigonal bipyramidal shap…
Five
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which is a substance that is made up of only one type of atom? mixture …
D. element
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oxygen difluoride (of₂) and magnesium oxide (mgo) are both oxygen compo…
A. $OF_2$
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ments, compounds, and mixtures which is a pure substance? soda carbon d…
# Breve explicación: Un sustantivo puro es una sustancia que tiene una composición química constante y definida. El sodio es una mezcla de gas carbonático, agua y otros aditivos. …
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question 14 (1 point) saved the geometry of the icl2 - molecule is best…
linear
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which of these elements forms the same number of covalent bonds (shared…
D. chlorine
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which best describes an element? an impure substance a pure compound a …
a pure substance
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question 13 (1 point) based on the vsepr theory, which one of the follo…
Question 13: HCN Question 14: linear
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which is a characteristic of mixtures? they are chemically bonded toget…
# Breve explicación: Las mezclas son compuestos formados por dos o más sustancias físicamente combinadas. No están unidas químicamente, no tienen proporciones fijas y no son susta…
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nitrogen forms covalent bonds with which of these elements? choose 2 an…
A. hydrogen, C. nitrogen
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the chemical formula for an emerald is be₃al₂(sio₃)₆. an emerald can be…
# Breve explicación: Los compuestos son sustancias puras formadas por dos o más elementos químicos combinados en proporciones fijas. La fórmula química del esmeralda, $Be_3Al_2(Si…
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a(n) ____ builds and maintains machines such as airplanes and physical …
D. engineer
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which method would be best for separating the components of a mixture t…
B. distillation
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a solid precipitate is formed from the reaction of lead nitrate and sod…
# Explicación breve: La filtración es un método común para separar sólidos de líquidos en una mezcla heterogénea. En este caso, el precipitado sólido se puede separar del líquido …
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a chemist is studying an unknown substance and could break the substanc…
pure substance
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question 15 (5 points) saved for each of the following substances, iden…
1. $F_2$: 1. dispersion (London) 2. $SiO_2$: 8. covalent network 3. $Al_2O_3$: 9. electrostatic (ionic) 4. $NH_3$: 5. hydrogen - bond 5. $ICl$: 4. dipole - dipole
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describing gasoline consider the picture of a gas pump. which type of g…
# Explicación: ## Paso 1: Comparar las calificaciones de octano Tenemos 87 (sin plomo), 89 (media - calidad) y 91 (premium). ## Paso 2: Determinar el valor más alto 91 es el valor…
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gasoline is a common fuel. most gas stations sell multiple grades of ga…
# Breve explicación: La gasolina es una mezcla de hidrocarburos con puntos de ebullición diferentes. La destilación es un método común para separar componentes de una mezcla basad…
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gasoline is a common fuel. most gas stations sell multiple grades of ga…
mixture
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elements, compounds, and mixtures describing gasoline considering the p…
Crude oil is a homogeneous mixture.
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you may think of petroleum as motor oil or gasoline. in fact, the oil t…
# Breve explicación: El petróleo crudo contiene muchos tipos diferentes de compuestos orgánicos. Un compuesto está formado por dos o más elementos químicos en proporciones fijas, …
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mohave county animal rescue and rehabilitation ii. washing cages a. for…
B. referring to the product guidelines.
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mohave county animal rescue and rehabilitation ii. washing cages a. for…
C. remains
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24 mark for review in which of the following liquids do the intermolecu…
D. $CH_2F_2(l)$
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a molecule exhibits the trigonal planar shape. how many electron groups…
First question: B. Three Second question: C. 120 degrees
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23 mark for review the attractions between the ccl₄ molecules that hold…
C. intermolecular attractions resulting from temporary dipoles
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(b) calculate the pressure of the co₂(g) in the container at 425 k. (c)…
\(P=\frac{34.8925n}{V}\ atm\) (assuming \(n\) is in moles and \(V\) is in liters) 2. **For part (c) - Using Answer - Explanation Format):**
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quiz #2 vsepr predicts an sbf5 molecule will be which of the following …
First question: B. trigonal bipyramidal Second question: C. trigonal pyramidal
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for parts of the free - response question that require calculations, cl…
The $CO_2(g)$ molecules will move faster and have more energetic collisions as the temperature is raised.
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the model below depicts the structure of a carbon - based molecule. in …
Carbohydrate
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question 6 (1 point) which of the following molecular geometries exhibi…
Question 6: E. linear Question 7: C. t - shaped
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question 4 (1 point) using the vsepr theory, predict that the shape of …
Question 4: B. linear Question 5: A. tetrahedral
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10. examine the following outer electron configuration and choose the c…
10. c. row 5 column 2 11. a. period 5, alkali metal 12. b. number of valence electrons 13. a. \(2+\) 14. c. \(2-\) 15. a. 1 16. c. 6 17. c. 3 18. d. 32 19. a. \(Ca\) 20. c. noble …
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which standard deviation would you prefer in a class distribution with …
$\sigma = 2$
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20 mark for review ne, hf, c₂h₆, ch₄ which of the substances listed abo…
B. HF, because its molecules form hydrogen bonds
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ionization energy is the energy needed to remove a valence electron fro…
1. a. 48 protons, 48 electrons, 72 neutrons 2. d. Sodium 3. a. a high density 4. a. unequal number of protons and electrons 5. b. mass number 6. a. potassium 7. c. decreases 8. d.…
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9 mark for review pure sample of which of the following compounds has t…
A. LiCl
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which of the following lists the substances f₂, hcl, and hf in order of…
D. $F_2 < HCl < HF$