化學
化學反應、化學計量、分子結構與元素性質。
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match the correct symbols with the names of elements. match the words i…
The chemical symbol Co stands for cobalt. The chemical symbol C stands for carbon. The chemical symbol Ca stands for calcium. The chemical symbol Cl stands for chlorine. The chemi…
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the next morning the dog was gone, as in my art i knew it would be; i h…
4. D. He knew that the dog would not be confined 5. D. Unyielding 6. D. He was not surprised that the dog had run away 7. C. place was 8. A. Fate 9. D. To describe a significant e…
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question 3 of 3 _____ are properties of microcurrent. (select all that …
Negative and positive polarity in one probe Current treats only a specific area, does not travel through the body Constant and direct current using a positive and negative pole Ex…
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____ are properties of tesla high - frequency current. (select all that…
Negative and positive polarity in one probe Uses one electrode made of glass or metal Thermal or heat - producing current with a high rate of oscillation Named after a Croatian el…
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question 1 of 3 _____ are properties of galvanic current. (select all t…
Named after an Italian doctor Extremely low level of electricity that mirrors the body's electrical impulses Negative and positive polarity in one probe Constant and direct curren…
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demonstration observe the demonstration and answer the following questi…
If the initial mass of Kool - Aid in Solution C is $m$ grams and the initial volume of Solution C is $V$ mL, the final concentration is $\frac{m}{V + 200}$ g/mL. Without knowing t…
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determine which of the following has the highest electronegativity. wri…
Fluorine
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permutations and combinations review name: 1. how many arrangements of …
453600 ### 2. How many arrangements can be made of word CHEMISTRY if the letters M, I, and S must appear together, in that order?
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barber and beauty services a career in cosmetology as a beautician or b…
In a vocational school
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answer each question about the following atom when it becomes an ion. p…
Potassium; K⁺; +1; loses; 1
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potassium determine the ionic radius. write the chemical symbol and cha…
1. Cation 2. K, +1 3. +1, loses, 1
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determine which of the following has the lowest electronegativity. writ…
Cesium
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determine which of the following has the largest atomic radius. write o…
rubidium
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isotope practice 1. here are three isotopes of an element: $_{6}^{12}c$…
1. - a. Carbon - b. Atomic number - c. Atomic mass - d. Protons: 6, Neutrons: 6 - e. Protons: 6, Neutrons: 7 - f. Protons: 6, Neutrons: 8 2. See above - calculated values for the …
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directions: check to see if the following equations are balanced or not…
1. Dark Blue 2. Light Blue 3. Dark Gray 4. Orange 5. Brown 6. Golden Yellow 7. Purple
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determine which of the following has the highest ionization energy. wri…
Hafnium (Hf)
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post - lab q13 what is the total amount of solids recovered? type your …
71.23%
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a student isolated the following from an unknown mixture: | component |…
$1.567$
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1. here are three isotopes of an element: $_6^{12}c$ $_6^{13}c$ $_6^{14…
| Isotope name | atomic # | mass # | # of protons | # of neutrons | # of electrons | | ---- | ---- | ---- | ---- | ---- | ---- | | Potassium - 37 | 19 | 37 | 19 | 18 | 19 | | Oxyg…
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just for fun, lets calculate how many agno₃ molecules are in those 0.10…
B. $6.02\times 10^{22}\text{ AgNO}_3$ molecules
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for beryllium chloride, 0.076 moles of silver nitrate are used. for mag…
D. 0.100 mol
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look at the reaction schemes in your journal or click the view image bu…
B. There should be twice as many moles of $AgNO_3$ as $XCl_2$
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in order for the gravimetric analysis to be valid, we want all of the c…
B. By ensuring silver ions are in excess
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in chemical reactions, what is the definition of a limiting reagent? a)…
D. The reactant that is completely consumed in the reaction.
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why is it important to use demineralized water? a) because demineralize…
d) Because demineralized water doesn't contain minerals
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what type of bond involves the sharing of electrons between atoms? ioni…
1. B. Covalent bond 2. C. Hydrogen bond
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atomic mass (route) 1. example: the natural distribution of the isotope…
For lutetium, the atomic mass is approximately $175.90\ amu$. For chlorine, the atomic mass is approximately $35.45\ amu$. For potassium, the atomic mass is approximately $39.10\ …
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5. which explanation best illustrates the cause - and - effect relation…
A. The energy from lightning heats up molecules, causing them to react to form new molecules (nitrates)
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what is the main goal of the investigation as described in the document…
There is no information about which document is referred to, so it's impossible to determine the correct answer. If we assume this is a chemistry - related investigation based on …
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the only equation youll ever need n (mol) x m (g) / m (g/mol) done day …
$M=\frac{m}{n}$
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what is the main goal of the investigation as described in the document…
There is no information in the question - body about which document is referred to. Without the content of the document, it's impossible to determine the main goal of the investig…
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what is the main goal of the investigation as described in the document…
No information about the document is provided, so it's impossible to determine the correct answer from the given options.
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how can you improve the accuracy of your results in the ame that compou…
C. By comparing results with known solutions
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where would you find the most particles: in the sahara desert at a dept…
B. There are roughly the same amount of particles on each picture
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what does the unique color emitted by a metallic element when burned in…
3. The energy levels are unique to each metal.
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if 1.00×10^18 singly - charged positive sodium ions flow from the anode…
$0.32\ A$
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atoms and molecules are way too small to be seen, even with a microscop…
b) You count them by mass
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read the excerpt from levitt and dubners freakonomics. if morality repr…
to lend credibility and additional support to their conclusion
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5. a poetic form that traditionally consists of 14 lines, written in a …
A. Sonnet
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use the periodic table to fill in the chart below for neutral atoms. se…
| Element | Chemical Symbol | Number of Protons | Number of Electrons | Number of Neutrons | | ---- | ---- | ---- | ---- | ---- | | Helium | He | 2 | 2 | 2 | | Hydrogen | H | 1 | …
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what are 3 signs that we talked about in virtual lesson that a chemical…
gas formation, pH change, odor
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true or false: in a chemical equation, the # of atoms in the reactants …
True
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chem 100 - introduction to chemistry - fall 2025 q13. which of the foll…
b) Blue light.
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use the periodic table to fill in the chart below for neutral atoms. se…
| Element | Chemical Symbol | Number of Protons | Number of Electrons | Number of Neutrons | | ---- | ---- | ---- | ---- | ---- | | Hydrogen | H | 1 | 1 | 0 |
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6. what is the term for the columns going down the periodic table? what…
6. Groups or families; number of valence electrons (for non - transition metals) 7. For main - group elements, use the group number (old 1 - 8A system) 8. Total electrons (atomic …
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write the symbols for the following elements 1. oxygen 2. hydrogen 3. c…
1. O 2. H 3. Cl 4. Na 5. F 6. C 7. He 8. N 9. Cu 10. S 11. Mg 12. Mn 13. Ne 14. Br 15. P 16. Ag 17. Pb 18. Fe 19. Ca 20. K 21. Copper 22. Potassium 23. Carbon 24. Gold 25. Zinc 26…
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question 15 (1 point) in the reaction: c + o2 → co2 what is the product…
C. $CO_2$
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question 14 (1 point) in the reaction: h2 + o2 → h2o which are the reac…
B. $H_2$ and $O_2$
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1. what is the group number for each of the following groups; a. noble …
1. a. Group 18 b. Group 2 c. Group 17 d. Groups 3 - 12 e. Group 1 2. Helium, Neon 3. Lithium, Sodium, Potassium 4. Scandium, Titanium 5. Periods; Same number of electron shells
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question 13 (1 point) what are the substances made after a chemical rea…
B. Products
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which pair of elements would most likely form a covalent bond? sodium a…
For the first question: Hydrogen and oxygen For the second question: Reactants
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what is the chemical name of nacl? sodium chlorine nitrogen chloride so…
1. C. Sodium chloride 2. True
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write the name of the element that corresponds to each of the following…
21. Copper 22. Potassium 23. Carbon 24. Gold 25. Zinc 26. Lead 27. Iron 28. Sodium 29. Sulfur 30. Aluminum 31. Calcium 32. Silver 33. Phosphorus 34. Oxygen 35. Iodine 36. Tin 37. …
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what type of bond forms when electrons are shared? ionic metallic coval…
1. C. Covalent 2. B. A nonmetal and a metal
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in co₂, what does the \2\ mean? two carbon atoms two oxygen atoms two m…
For the first question: B. Two oxygen atoms For the second question: False
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what does a chemical formula show? the cost of a chemical the number an…
What does a chemical formula show? - B. The number and types of atoms in a substance In H₂O, how many hydrogen atoms are there? - B. 2
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4. which of the following correctly describes the trend in atomic radiu…
Atomic radius decreases because protons pull the electrons closer.
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what is a compound? a type of atom atoms that do not bond together two …
Question 1: C. Two or more atoms bonded together Question 2: True
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write the symbols for the following elements. 1. oxygen 2. hydrogen 3. …
1. O 2. H 3. Cl 4. Na 5. F 6. C 7. He 8. N 9. Cu 10. S 11. Mg 12. Mn 13. Ne 14. Br 15. P 16. Ag 17. Pb 18. Fe 19. Ca 20. K
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in an ionic bond, the two elements that come together to form one * 1 p…
For the first question: C. nonmetal For the second question: Ionic bond
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in an ionic bond, electrons are... * 1 point shared transferred split
Transferred
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there are 3 terms we should know when talking about dissolving substanc…
The salt is the solute. The water is the solvent. The salt - water mixture is the solution.
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13.atom a: 11 protons, 12 neutrons, 11 electrons atom b: 11 protons, 14…
Atomic number: Same (11 for both). Mass number: Different (23 for Atom A, 25 for Atom B). Classification: Same element (sodium) as they have the same atomic number.
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why is water a great solvent? ○ it has more oxygens that hydrogens ○ it…
it is capable of dissolving more substances than any other liquid
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clear all elements in the same group have similar chemical properties. …
Elements in the same group have similar chemical properties.
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water molecules are connected to other water molecules by _____________…
B. hydrogen
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why is water considered a polar molecule? it has unequal sharing of ele…
It has unequal sharing of electrons (H's are positive, O's are negative)
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15. which of the following explains why atoms of the same element can h…
They have different numbers of neutrons
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the bonds within water are the most missed questions on the exam. pleas…
B. covalent
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13. determine the periodic trends best represents the general trend of …
It increases as you move down a group.
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10. a sample of copper contains 69.2% of cu - 63 (62.929 amu) and 30.8%…
$63.64$ amu
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7. determine which of the following statements correctly compares cesiu…
Cs has a larger atomic radius and lower ionization energy and lower electronegativity.
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anatomy of an atom the basic model what are atoms made of? scientists h…
1. The nucleus 2. Subatomic particles 3. Protons and neutrons 4. Neutrons 5. Electrons 6. Negatively - charged particles that orbit the nucleus in a "cloud" at nearly the speed of…
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3. the average atomic mass is a average of the isotopes of an element, …
weighted - average; abundances
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anatomy of an atom the basic model what is located at the center of an …
1. Protons and neutrons 2. Neutrons 3. Electrons 4. Negatively - charged subatomic particles that orbit the nucleus 5. A tabular display of the chemical elements, organized by ato…
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constructing an evidence - based argument use the scaffold below to cri…
Investigation Question: Is our Sun releasing energy due to chemical or nuclear reactions? Best - supported claim: The Sun is releasing energy due to the process of nuclear fusion …
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practice: isotope calculations #2 1. complete the following table nucle…
1. | Nuclear Notation | Atom or Ion? | Atomic # | Mass # | # of Protons | # of Neutrons | # of Electrons | |---|---|---|---|---|---|---| | $^{24}_{11}Na$ | Atom | 11 | 24 | 11 | 1…
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what of the following best describes soil liquefaction? a when saturate…
A. when saturated soil behaves like a liquid
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what is the atomic mass number equal to? what is the atomic number equa…
1. The sum of protons and neutrons. 2. The number of protons. 3. An atom of an element with the same number of protons but different number of neutrons. 4. A tabular display of ch…
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constructing an evidence - based argument use the scaffold below to cri…
The Sun is releasing energy due to nuclear reactions. The evidence includes the Sun's long - term energy output, core conditions (high temperature and pressure), its mass, and spe…
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04 question (1 point) write the chemical equation describing the comple…
$2C_8H_{18}(l)+25O_2(g) ightarrow16CO_2(g)+18H_2O(g)$
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part 3 (1 point) remember that chemists typically do not include a coef…
1; 3; 1; 6
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when balancing a chemical equation, which of the following is/are permi…
Part 1: B. placing a coefficient in front of a formula Part 2: A. O B. F C. H
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44. ripening is the process of bananas ripening a chemical change or a …
- 44. Es un cambio químico. - 45. Es un cambio físico.
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part 1 (1 point) in a balanced chemical equation, does the number of mo…
Part 1: no Part 2: 3 Part 3: 2
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a ____________ speeds up a chemical reaction. enzymes are an example of…
B. Catalyst
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1. fill in the blank: fat is made up of _, molecules that are all diffe…
1. fatty - acid 2. unsaturated 3. Fried snacks (e.g., French fries), baked goods (e.g., cookies), some margarines 4. partially hydrogenated oil
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43. classify each as a physical change or a chemical change. a. breakin…
a. Cambio físico b. Cambio físico c. Cambio químico d. Cambio químico e. Cambio químico
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why does increasing the speed of molecules increase reaction rate? mole…
C. Molecules move faster, increasing both the chance and energy of collisions.
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how does increasing temperature generally increase reaction rate? at hi…
At higher temperatures, a greater proportion of particles have the sufficient energy, aka the activation energy, $E_a$, necessary for a successful collision.
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the amount of energy necessary to move from reactants to the transition…
C. Activation energy
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which curve on the energy diagram shows the reaction that ran slower? s…
Solid gray curve, because it has a higher activation energy
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reactants will successfully move forward in the reaction when... they c…
they collide with the proper orientation and sufficient energy.
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42. label each set of diagrams in figure 23 as a physical or a chemical…
No se puede determinar la respuesta sin ver la Figura 23. Se necesitan los diagramas para clasificar cada conjunto como un cambio físico o químico.
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b. identify the type of reaction as synthesis, decomposition, single - …
1. Double - replacement 2. Single - replacement 3. Double - replacement 4. Single - replacement 5. Synthesis
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a. classify the following reaction as synthesis, decomposition, single …
1. Double - replacement reaction 2. Decomposition reaction 3. Double - replacement reaction 4. Single - replacement reaction 5. Combustion reaction
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40. boiling water at what temperature would 250 ml of water boil? 1000 …
# Explicación detallada: ## Paso 1: Punto de ebullición del agua A presión atmosférica normal (1 atm), el agua hierve a 100 °C independientemente del volumen. Entonces, tanto 250 …
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7 • • • → • • • single replacementdisplac 8 • • → • • 9 caco₃ → cao + c…
8. Synthesis 9. Decomposition 10. Double - replacement 11. Single - replacement 12. Synthesis 13. Neutralization (Double - replacement) 14. Decomposition 15. Single - replacement
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types of chemical reactions identify the type of chemical reaction (syn…
1. Single displacement 2. Double displacement 3. Decomposition 4. Synthesis 5. Decomposition 6. Double displacement 7. Single displacement
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question 1 1 pts the half - life of a radioisotope is 104.3 years. how …
$2.63$