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 mass number of an atom that has 12 protons, 13 neutrons, an…
D. 25
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how does an atom change if all of its electrons are removed? the atoms …
The atom becomes positively charged
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what is the net charge of an atom that has 12 protons, 13 neutrons, and…
C. -1
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for a gas at a given temperature, what is true about the speed of those…
The molecules move at a range of speeds; the greater the temperature, the wider the range.
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what is most likely true of an atom with a mass of 15 amu? there are 15…
The total number of protons and neutrons is 15.
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12. how many lone pairs of electrons are on the central atom in the lew…
a. 0
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what changes when you add a neutron to an atom? ○ its mass increases by…
Its mass increases by 1.
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doug is testing out the following reaction: na2co3 + 2hcl → 2nacl + h2o…
D. 91.7 g, because this mass accounts for all equipment, reactants, and products created in the reaction.
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for a gas at a given temperature, the molecules move at a range of spee…
The greater the temperature, the wider the range of speeds.
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at a given temperature, what is true of all gas molecules? they have th…
They have the same average kinetic energy.
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at the same temperature, what is true of lighter, aka less massive, mol…
C. Lighter molecules move faster.
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how is the velocity of gas molecules impacted by temperature? the veloc…
C. The average molecular velocity increases as temperature increases.
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deeper into kinetic molecular theory review this graph of samples of ga…
The greater the mass of the gas, the slower the average speed.
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example#2 : mixture of (water )__________ and (hydrogen peroxide)______…
a) Mixture b) Compound c) Compound
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slide 22 : study the diagram carefully. what difference do you notice b…
Slide 22: In a mixture of two elements, they retain individual properties and can be separated physically; in a compound, they combine chemically in a fixed - ratio to form a new …
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73. when 0.5141 g of biphenyl (c₁₂h₁₀) undergoes combustion in a bomb c…
$\Delta_{r}U = 6321.5\ kJ/mol$, $\Delta_{r}H = 6315.3\ kJ/mol$
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slide 19:what is meant by a phase? slide 20: how many phases in a heter…
Slide 19: A physically distinct form of matter. Slide 20: Multiple phases. Slide 21: One phase.
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balance the equations by adding whole numb 1. h₂ + o₂ → h₂o 2. n₂ + h₂ …
1. $2H_2+O_2 = 2H_2O$ 2. $N_2 + 3H_2=2NH_3$ 3. $C_3H_8+5O_2 = 3CO_2 + 4H_2O$ 4. $4Fe+3O_2 = 2Fe_2O_3$ 5. $2Al + 6HCl=2AlCl_3+3H_2$ 6. $2KClO_3=2KCl + 3O_2$ 7. $2Na+2H_2O = 2NaOH +…
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which option is an example of a chemical change? spreading peanut butte…
digesting a sandwich
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which option is an example of a chemical change? a dicing an onion b mi…
D. digesting a salad
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which of these is an example of a physical change? baking bread toastin…
breaking bread
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which statement is true of a chemical reaction? energy is always releas…
Energy is either released or absorbed.
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which property is a chemical property of a substance? o density o boili…
D. flammability
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the periodic table of elements is shown. select all of the elements tha…
Elements in the same group as oxygen (Group 16) such as sulfur, selenium, tellurium, polonium are likely to share properties with oxygen. In the given options, if there are elemen…
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icp vocabulary test 1 name place the number beside the letter 1 gravity…
1. B. The natural force of attraction between objects 2. S. High energy phase of matter 3. V. Matter with no definite shape but with a definite volume 4. M. Measure of the amount …
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a student is examining the liquid mercury inside a thermometer. if the …
A. The liquid is a pure substance because it is made up of elements.
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step 1: iron and sulfur are mixed together in a test - tube. step 2: th…
C. Step one contains a mixture of elements, which are physically combined in step two, forming a new compound in step three.
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daniella wrote a table comparing pure substances and mixtures. pure sub…
A. Elements and compounds are considered mixtures.
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look closely at the illustration below, which shows a part of the perio…
B. He and Ne
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slide 9: what is mud a mixture of? slide 10: why is air considered a mi…
- Slide 9: Mud is a mixture of soil and water. - Slide 10: Air contains nitrogen, oxygen, carbon - dioxide, argon and other trace gases which are not chemically combined and can b…
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question 1 2 pts which subatomic particles are found in the nucleus? (c…
protons neutrons
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slide 9: what is mud a mixture of? slide 10: why is air considered a mi…
Slide 9: Soil, water, and sometimes organic matter. Slide 10: It contains nitrogen, oxygen, carbon - dioxide, argon and other trace gases that are not chemically combined. Slide 1…
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6. acetonitrile (ch3cn) is an important industrial chemical. among othe…
C. Acetonitrile has one triple bond.
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15) which process involves the movement of rock pieces by natural agent…
15. C. Erosion 16. A. The cryosphere melts - sea level rise in the hydrosphere. 17. A. It is made of solid iron & nickel, with heat & pressure. 18. B. Rock & debris move downslope…
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30 which substance can be separated into its components by a physical p…
C. Saltwater
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29 which of the following mixtures can be classified as homogeneous? a …
A. Sugar in tea
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28 which substance category has a consistent composition and distinct p…
A. Pure substance
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27 iron (fe) is classified as a mixture. a false b true
A. False
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26 oxygen (o2) is classified as a compound. a false b true
A. False
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25 a molecule of water (h2o) is classified as a compound. a true b false
A. True
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24 what type of mixture is air considered to be? a element b heterogene…
C. Homogeneous mixture
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23 why is the classification of matter important in chemistry? a it hel…
A. It helps in developing new materials and technologies
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22 what type of mixture is formed when two or more substances combine w…
B. Mixture
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slide 8: more examples of mixtures. name the mixture and list its parts…
1. Air; Nitrogen, oxygen, argon, carbon - dioxide, trace gases 2. Salt - water; Salt, water 3. Soil; Minerals, organic matter, air, water, living organisms 4. Brass; Copper, zinc
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21 which of the following is an example of a compound? a oxygen (o2) b …
D. Water (H2O)
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20 which of the following describes a characteristic of homogeneous mix…
A. Particles evenly distributed throughout
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part b read each scenario. decide whether a physical or chemical change…
| Scenario | Physical or Chemical Change? | Evidence | |--|--|--| | 2 | Chemical | Formation of black - charred substance and smoke | | 3 | Chemical | Formation of rust (iron oxid…
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19 in what type of mixture are particles large enough to eventually set…
C. Suspension
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18 in which type of mixture do the components retain their individual p…
A. Mixtures
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17 which mixture cannot be easily separated and has particles that do n…
A. Colloid
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slide 6: cornflakes/cereal and milk is a mixture. it is a mixture of a …
Size (varying), color (green - red - yellow etc.), ripeness (unripe - ripe)
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16 what property of substances helps scientists predict material behavi…
C. Consistent atomic and molecular structure
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15 bronze, an alloy of copper and tin, is classified as a mixture. a fa…
B. True
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14 what distinguishes compounds from elements based on their compositio…
C. Have fixed ratios of atoms from different elements
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as with the less precise balance, there is also uncertainty in the meas…
lower value: 150.87 g, upper value: 150.89 g
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13 which of the following is not a characteristic of pure substances? a…
C. Can be separated into components by physical means
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the chemical structure that is shown below is a multiple choice triglyc…
A. triglyceride
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12 air is classified as a pure substance. a true b false
B. False
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complete the following statement using this data. this mass measured on…
falls within
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11 a salad is classified as a homogeneous mixture. a true b false
B. False
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10 how are elements different from compounds? a compounds are only foun…
B. Elements are made of one type of atom, compounds are not
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9 which of the following best describes a colloid? a particles settle o…
D. Tiny particles that scatter light but don't settle
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8 table sugar (c12h22o11) is classified as a compound. a false b true
B. True
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7 what kind of mixture is milk considered to be? a suspension b solutio…
D. Colloid
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6 saltwater is classified as a mixture. a true b false
A. True
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5 how can muddy water be classified in terms of matter? a colloid b ele…
D. Suspension
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4 what is the simplest form of matter composed of only one type of atom…
A. Element
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3 carbon dioxide (co2) is classified as a mixture. a false b true
A. False
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2 pure gold (au) is classified as an element. a true b false
A. True
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1 which of the following is a property of a heterogeneous mixture? a vi…
A. Visibly distinct components
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intro: 1.1 why study chemistry? overview: • helps us understand the fun…
The reasons for studying chemistry are understanding matter and interactions, explaining natural phenomena, enabling new developments, making informed decisions, preparing for car…
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slide 3: a salad bar provides a range of items, such as lettuce, tomato…
Slide 4: A mixture is a combination of two or more substances where the substances keep their individual identities and are not chemically bonded. Slide 5: Physical blending means…
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question 3 write the formula for the following compound: potassium brom…
A. KBr
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question 2 atomic mass = protons + electrons true false
B. False
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slide 3: a salad bar provides a range of items, such as lettuce, tomato…
A mixture is a combination of two or more substances where the substances keep their individual identities and properties, and are not chemically bonded, with variable proportions.
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question 13 (1 point) listen what coefficient would go in front of ammo…
B. 2
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which of the following is the balanced equation for the reaction betwee…
B. 2H2 + O2 -> 2H2O
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question 11 (1 point) which statement best describes the law of conserv…
The mass of the reactants is equal to the mass of the products.
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question 10 (1 point) what is the name of the following compound? h2o d…
B. Dihydrogen monoxide
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what is the name of the following compound? alcl3 monoaluminum chloride…
B. Aluminum chloride
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periodic table families 1. what are the elements nitrogen n, phosphorou…
1. Pnictogens 2. Periods 3. 18 4. 7 5. Metals 6. Right side 7. Chlorine (Cl) 8. Nickel 9. He, Ne 10. Fe, Cu
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question 8 (3 points) check all of the properties that describe an ioni…
involves transfer of electrons nonmetal + metal solid at room temperature
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name: xxxx date/block: directions: complete the worksheet as you go thr…
Slide 2: pure substances and mixtures Slide 4: A combination of two or more substances in which the substances retain their distinct identities and can be present in varying amoun…
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question 7 (1 point) listen how many different elements are in the visu…
2
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question 6 (1 point) listen how many atoms are in the visual below? met…
5
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what is the visual below an example of? methane ch4 element compound at…
B. Compound
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fill in the chart below. the first row has been completed as an example…
a. Fluorine (F) b. Oxygen (O) c. Lithium (Li) d. Uranium (U) e. Cerium (Ce) f. Calcium (Ca) g. Iron (Fe) h. Helium (He)
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elements on the right side of the periodic table who are most likely li…
non - metals
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question 2 (1 point) which family of the periodic table have 1 valence …
A. alkali metals
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use the periodic table below to answer the following question. the elem…
Period
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in an ionic bond, the two elements that come together to form one * 1 p…
First question: C. nonmetal Second question: Ionic bond
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energy is released during which phase changes? check all that apply. su…
C. freezing, D. depositing, E. condensing
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which statements describe phase changes? check all that apply. particle…
Particles in gas move fast enough to make more attractive forces when the gas condenses. Attractive forces between the particles in a liquid are broken when a liquid boils. Attrac…
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read this excerpt from walt whitmans poem \i hear america singing\ from…
A. present a poem with a natural, conversational rhythm.
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question 15 mark this question when attending a birthday party, knowing…
C. a social schema
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write out the rhyme scheme for the following nursery rhyme: wee willie …
(17) aabbcc (18) abba abba cde cde (19) Divided into an octave (first 8 - lines) and a sestet (last 6 - lines) (20) 10 syllables per line (21) 14 (22) The first line of the sestet…
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kayla and emma are best friends, and theyre at emmas house studying for…
A. Emma must decide whether or not to help Kayla cheat on the chemistry test.
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read this passage: kayla and emma are best friends, and theyre at emmas…
B. She thinks about pretending to be sick to avoid the situation, but she goes to school and tells Kayla that she doesn't feel comfortable cheating and refuses to give Kayla the a…
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read this stanza from allen ginsbergs \a supermarket in california.\ wh…
The long - line structure imitates stream - of - conscious thought.
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c. describe the symmetries of the hydrogen peroxide molecule. select th…
A. The hydrogen peroxide molecule has the following rotational symmetry(ies) 180, point symmetry, and does not have reflectional symmetry.