化学
化学反应、化学计量、分子结构与元素性质。
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this section describes what happens to chemical bonds during chemical r…
1. A process that changes one set of chemicals into another set of chemicals. 2. Reactants: Starting substances in a chemical reaction. Products: Substances produced by a chemical…
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16. all of the following are renewable energy sources that will never r…
16. c) Wood 17. a) The Clean Air Act of 1972 reducing smog and other harmful pollutants in the atmosphere 18. d) Clean Water Act
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which substance is a compound? o salt o phosphorus o sulfur o oxygen
salt
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3. gases from the eruption are released into the air and combine with w…
B. Atmosphere & Hydrosphere — acid rain changes the chemical composition of the ocean
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question 12 of 13 how many electrons can you have in the first ring? 18…
B. 2
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comprehension check questions chem 2.2_periodic table & atomic calculat…
| Element (Nuclear notation) | Atomic # | Mass # | \(\#p^{+}\) | \(\#n^{0}\) | \(\#e^{-}\) | |---|---|---|---|---|---| | \(^{27}Al\) | \(13\) | \(27\) | \(13\) | \(14\) | \(13\) |…
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question 11 of 13 elements in the same column, or family/group, have th…
True
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question 10 of 13 elements in the same column, or family/group, have th…
C. Electrons (specifically valence electrons)
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question 9 of 13 the arrangement of the periodic table is random. true …
B. False
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directions: write the correct answer in the space provided. write the w…
9. True 10. False 11. True 12. True 13. False 14. N/A 15. N/A 16. N/A 17. N/A 18. N/A 19 - 25: N/A
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question 8 of 13 what is inside the nucleus of an atom? shells electron…
C. Neutrons, D. Protons
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4. fill in the following chart: (assume all atoms are electrically neut…
| Element symbol | Atomic number | Mass number | # of protons | # of neutrons | # of electrons | |---|---|---|---|---|---| | O | 8 | 16 | 8 | 8 | 8 | | Al | 13 | 27 | 13 | 14 | 13…
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question 7 of 13 elements can combine with other elements to create com…
True
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give the percent yield when 28.16 g of co2 are formed from the reaction…
$25.00\%$
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given the following equation select the appropriate stoichiometric rati…
2 mol NO : 2 mol NH₃
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question 4 of 13 everything around us is made up of elements true false
True
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question 3 of 13 the atomic number is the number of- neutrons electrons…
C. Protons
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question 1 match each term with its definition limiting reagent theoret…
limiting reagent: reactant which produces the least amount of product Theoretical yield: amount of product you can produce based off of the limiting reagent % yield: percentage of…
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3. fill in the following chart. dont forget to come the isotope symbol …
| Element Symbol | Atomic number | Mass number | # of protons | # of neutrons | # of electrons | | ---- | ---- | ---- | ---- | ---- | ---- | | $_{19}^{39}K^+$ | 19 | 39 | 19 | 20 …
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directions: place the correct letter in the space on the left. use all …
1. A. Flames 2. D. Lab apron 3. B. Safety Goggles 4. D. Electric Shock 5. B. Heat Resisting Gloves 6. C. Fumes 7. B. Hand washing 8. A. Poison
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read passage 1: we real cool by gwendolyn brooks and then respond to qu…
B. It uses line length to show how the pool players' actions and lives are sudden and disconnected.
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water molecules move faster as the temperature increases. what evidence…
The change of water from ice to liquid water and then to steam as temperature increases shows that water molecules move faster. In ice, molecules are relatively fixed; in liquid w…
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consider these intermediate chemical equations. ch₄(g) + 2o₂(g) → co₂(g…
$\mathrm{CH}_{4}(g)+2\mathrm{O}_{2}(g) ightarrow\mathrm{CO}_{2}(g)+2\mathrm{H}_{2}\mathrm{O}(l)$
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states of matter quiz cp chemistry a.0 / module 2: basics of matter 3. …
B. solid
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states of matter quiz cp chemistry a 0 / module 2: basics of matter 2. …
B. Gas, because the particles are very far apart from each other.
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in the final chemical equation, nacl and o2 are the products that are f…
multiplying the first equation by 2.
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read the following information from a material safety data sheet (msds)…
A. Remove the shirt, and rinse the skin with water.
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consider these intermediate chemical equations. no (g) + o₃ (g) → no₂ (…
$-304.1kJ$
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consider these intermediate chemical equations. 2p (s) + 3cl₂ (g) → 2pc…
$PCl_3$
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when two intermediate chemical equations are combined, the same substan…
It is a reactant in one intermediate reaction and a product in the other.
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click the \investigation\ tab and break all the bonds in the reactants.…
- 802
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the table shows the enthalpy values for the different bonds found in th…
$\Delta H=(4\times413)+(2\times495)-(2\times799)-(4\times463)$ (but from the given options, the part related to bonds broken in $CH_4$ is $\Delta H=(4\times413)+\cdots$ so the rel…
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what can happen to solar radiation when it enters earths atmosphere? it…
It is absorbed or reflected as it travels to Earth’s surface.
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chemical bonds have bond enthalpies that describe how much energy is ab…
Total number of C - H bonds in the reactants: 4 Total number of $O = O$ bonds in the reactants: 2 Total number of $C = O$ bonds in the products: 2 Total number of O - H bonds in t…
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a high school chemistry student is tasked with determining the density …
C. 23.7 $cm^{3}$
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select basic polar non - polar acidic select
For the top structure: Polar, Acidic For the bottom structure: Basic
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a sample of metal is heated until it melts and begins to glow red. when…
FALSE
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causes of drought 1 several factors contribute to drought: 2 low precip…
- The four factors that contribute to drought are low precipitation, changes in climate, water quality issues, and high demand for freshwater. - The main idea of this section is t…
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someone is working in their garden, giving some plants a liquid fertili…
FALSE
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select the correct text in the passage. in this excerpt from annus mira…
Methinks already from this chemic flame / I see a city of more precious mould / Rich as the town which gives the Indies name / With silver paved, and all divine with gold
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a liquid in a container is heated until it turns to a gas. this is enou…
FALSE
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when two colorless liquids are mixed together, the formation of a solid…
reaction
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4. if your job is to test the amount of lead found in paint samples, wh…
D. analytical chemistry
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if you mix two clear, colorless liquids together, which of the followin…
C. A solid appears in the tube and settles to the bottom.
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2. chemicals are used for preserving food products. it helps them by in…
Biochemist
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select the correct answer. what is the greatest difference between ben …
B. tone
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two reactants are mixed in a test tube, and the test tube becomes very …
heat
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a solid that forms and settles out when two or more solutions are mixed…
c. precipitate
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a solid and a liquid are mixed in a test tube. which of the following o…
A. The mixture changes color to a deep blue. C. The mixture starts to fizz as a gas is released. D. The test tube becomes colder as the substances are mixed.
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when zinc metal is mixed with hydrochloric acid, vigorous production of…
Hydrogen gas
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which of the following correctly describes changes in energy during a c…
B. Energy may be either absorbed or released during a reaction.
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if a powdered solid were mixed with a liquid which of the following obs…
d. The mixture starts fizzing and releasing gas.
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12 multiple choice 5 points model of a na atom is shown below: b. what …
1. Option Text
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15 multiple choice 5 points the image shows a model for a lithium atom:…
4
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12. the substances that start a chemical reaction are called ____. ente…
reactants
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11. the substances produced in a chemical reaction are called ______.
products
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10 multiple choice 5 points the table shows the number of each of the t…
C. 1 and 4
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10. during a chemical reaction a chemical bonds break. b matter is dest…
A. chemical bonds break
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5) how long do emotions last chemically in the body? (a) 90 minutes (b)…
C. 90 seconds
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9. when lead nitrate and potassium iodide are mixed, what color precipi…
Yellow
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41 - 55: number of neutrons for sulphur-35
19
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8. if you heat a red powder to a high temperature and observe that it c…
TRUE
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7. when zinc metal is mixed with hydrochloric acid, vigorous production…
Hydrogen gas
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6. which of these metals is least likely to be involved in chemical rea…
A. gold (Au)
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5. what compound forms when zinc reacts with sulfur? enter the answer s…
Zinc sulfide (ZnS)
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4. the ability of matter to easily combine chemically with other substa…
A. reactivity
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3. which of these is a chemical change? a water evaporating b dissolvin…
d. baking a cake
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2. which of the following is/are true? a mixing an acid with base to pr…
C. Tarnishing of silver is a chemical change
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1. all of the following are chemical changes except a iron rusting, b i…
B. ice cubes melting
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remove the two oxygen atoms and observe that the claws get replaced by …
Energy released to form one O - H bond: 463 kJ/mol Energy released to form one H₂O molecule: 926 kJ/mol Total energy released to form two H₂O molecules: 1852 kJ/mol
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click the \investigation\ tab. the energy required to break a chemical …
Total energy required to break both single H - H bonds: 872 kJ/mol Total energy required to break both bonds in the O=O molecule: 498 kJ/mol Total energy absorbed to break all the…
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element #72 hafnium has an atomic mass of 178. how many neutrons are th…
106
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consider these equations. ch₄(g) → c(s) + 2h₂(g) δh₁ = 74.6kj c(s) + 2c…
represents the overall enthalpy of reaction
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consider these equations. ch₄(g) → c(s) + 2h₂(g) δh₁ = 74.6kj c(s) + 2c…
has a magnitude that is less than that of B
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consider these equations. ch₄(g) → c(s) + 2h₂(g) δh₁ = 74.6kj c(s) + 2c…
74.6 kJ
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what can a person do to limit exposure to x - rays? wear sunblock avoid…
wear a protective lead vest
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which option correctly shows the concentration of h₃o⁺ ions in pure wat…
$1.0\times10^{-7}\ mol/L$ (corresponds to the third - option from the list in the question)
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which pattern in electronegativity do elements in the periodic table di…
Electronegativity increases from left to right within a row of the periodic table.
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use the reaction to answer the question. hcl + h₂o → cl⁻ + h₃o⁺ which s…
HCl is an acid, and Cl⁻ is its conjugate base
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which statement best describes the difference between a substance with …
The substance with the lower pH has 1,000 times as many hydrogen ions per volume of water.
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how are acids and protons related? (1 point) acids are substances that …
An acid can donate protons to a base when they react.
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exercise 3.31 - enhanced - with expanded hints view available hint(s) r…
Molecular: $\text{PCl}_3$, $\text{CH}_4$ Ionic: $\text{SrF}_2$, $\text{Fe}_2\text{O}_3$
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which of the following are chemical changes? select all correct answers…
Wood burning to form ash, Hydrogen and oxygen forming water
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6 which of the following is an important thing to consider when choosin…
6. Whether there are monthly fees or minimum balance requirements. 7. You'll likely have 24 - hour access to your money.
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select the correct terms to complete the statement: a homogeneous mixtu…
D. Homogeneous, heterogeneous
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convert word equations into chemical equations classify each chemical r…
1. S, $Mg + S ightarrow MgS$ 2. D, $2NaOH ightarrow Na_2O + H_2O$ 3. DD, $CaS+2HCl ightarrow CaCl_2 + H_2S$ 4. SD, $Cl_2 + SrI_2 ightarrow SrCl_2+I_2$ 5. D, $2Ag_2O ightarrow 4Ag …
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select the correct terms to complete the statement: an intensive proper…
Intensive, physical
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what is the purpose of a detailed chemical analysis in the context of m…
C. To identify the components
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if an electron is promoted into a higher energy level within an atom, w…
create more half - filled orbitals that are available to accept or share electrons with different atoms
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what does the acronym \oil - rig\ stand for in the context of redox rea…
Oxidation is losing electrons; reduction is gaining electrons.
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which option correctly describes an oxidation - reduction reaction? a t…
a transfer of electrons
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porcelain originated in china around 2,000 years ago, but its productio…
B. It emphasizes the longstanding European desire to create porcelain themselves.
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16. in the diagram below, label each phase and phase change indicated. …
1. Melting (Solid to Liquid) 2. Liquid 3. Condensation (Gas to Liquid) 4. Vaporization (Liquid to Gas) 5. Solid
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artificial turf is composed of blades of fake grass. between each blade…
B. harmful
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multiple choice 1 point in which of these compounds are there twice as …
$H_2SO_4$
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13. label each of the following as an element, compound, homogeneous mi…
a. Element b. Homogeneous mixture c. Element d. Heterogeneous mixture e. Homogeneous mixture f. Compound g. Heterogeneous mixture h. Compound
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how many hydrogen (h) atoms are in 4nh₃? 1 4 3 12
D. 12
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21 multiple choice 1 point how many total atoms make up 2ba(io₃)₂? 18 1…
18 (corresponding to the first option)
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after which action would the concentration of a solution remain constan…
B. removing solution from the container
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atomic structure worksheet draw an atom below and label the following: …
| Subatomic Particle | Electrical Charge | Location in Atom | Relative mass (amu) | | ---- | ---- | ---- | ---- | | Electron | - 1 | Outside the nucleus in electron - shells | ~0 …