化学
化学反应、化学计量、分子结构与元素性质。
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pregunta de opción múltiple silvers atomic symbol (or abbreviation) is …
Neither of the given options is correct. The atomic symbol "Ag" for silver is from its Latin name "argentum".
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two atoms that have different numbers of protons are o different isotop…
B. Different elements
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what type of atom is element c? c 12 protons 12 neutrons 11 electrons i…
A. Ion
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what is the atomic number of this element? c 12 protons 12 neutrons 11 …
12
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the defining trait of an element is its _______________, which is equal…
Atomic number
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question 17 what does it change in an ion? the number of electrons the …
The number of electrons
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stion 16 what type of atom is this? o normal atom o anion o cation o is…
Isotope
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covalent bonding basics manipulatives directions: for each set of atoms…
Lewis - dot structure: H:Cl (with a single bond between them and 3 lone pairs on Cl) Ball - and - stick diagram: A single stick connecting a H ball and a Cl ball with 3 sets of 2 …
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what type of atom is this? 24 2+ mg 12 anion isotope cation neutral atom
C. Cation
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what type of atom is this?
A metal - ion (magnesium ion)
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what charge does an atom have when it gains electrons? positive unpredi…
C. Negative
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question 13 calcium has the atomic number 20. if it has a mass number o…
D. 26
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when two atoms of the same element have different masses, they are call…
B. Isotopes; Neutrons
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# protons ______ # neutrons ______ 82 pb lead 207
# protons: 82 # neutrons: 125
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of most common isotope table will be an average of all isotopes) 79 au …
# protons: 79 # electrons: 79
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how many neutrons are in the isotope pictured below? 63 29 cu
34
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atomic number 1 h hydrogen 1 atomic mass
Atomic number: 1 Atomic mass: 1
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employees exposed to hazardous chemicals must be trained in all these a…
There is no correct "except" option as all listed areas are necessary for training.
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how do we determine if a reaction is at equilibrium? q = products/react…
15) The reaction - quotient, which is the ratio of the concentrations of products to reactants at a particular moment in the reaction. 16) C. The reaction is already in a dynamic …
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in which workplaces are written hazard communication programs not requi…
Where employees deal with sealed containers
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osha - required hazard communication training must include all of the f…
D. Chemical hazard cost analysis
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81. if φ is defined such that aφb = b(a + b), what is the value of 5φ4?…
C. 36 ### 82.
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use your carbon compounds: part 1 notes and the information provided be…
1. Carbon 2. Carbon (C), Hydrogen (H), Nitrogen (N), Oxygen (O), Phosphorus (P), Sulfur (S) 3. A substance consisting of two or more elements with a unique composition. Example: W…
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82. hakim, lisa, and oscar all play instruments. hakim plays the same i…
D. None of the above must be true ### 83.
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21) a catalyst usually lowers the energy required to initiate the react…
21) True 22) False 23) Hot water
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17) what causes the interactions between gas particles? oa) ionic bonds…
17. D. Intermolecular forces 18. A. Low temperature, D. High pressure 19. A. There is no attraction between the molecules, C. Collisions between molecules are elastic, E. The mole…
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what is the number of moles of gas contained in a 3.0l vessel at 300k w…
1. First problem: None of the given options are correct. 2. Second problem: A. $0.0069\ mol$ 3. Third problem: None of the given options are correct.
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1. a 25.0 l tank contains hydrogen (h₂) gas at a temperature of 149 k a…
1. $3.09\ mol$ 2. C. L
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81. if ★ is defined such that a★b = b(a + b), what is the value of 5★4?…
81. None of the options are correct with the correct calculation using \(a abla b=b(a + b)\) (if there is a mis - type in the options). 82. D. None of the above must be true.
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worksheet nuclear radiation what is nuclear chemistry give three compar…
1. Nuclear chemistry is the study of nuclear processes and radioactive substances. 2. | Chemical reactions | Nuclear reactions | |--|--| | Small energy changes | Large energy chan…
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ch 09 five elements of hair design quiz question 1 of 2 6 points fill i…
form, space, design texture, flat iron, relaxers, permanent waves
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what is the process of sublimation? the electric company in your commun…
(12) The substance pulls energy from substances around it, which weakens the attraction between the particles in the solid. When the attraction weakens enough, the solid changes d…
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identify the elements in the following equation. $_2^4he + _7^{14}n \to…
The elements are Helium (He), Nitrogen (N), Oxygen (O), and Hydrogen (H).
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identify the elements in the following equation. $_2^4he + _7^{14}n \to…
The elements are helium ($\ce{He}$), nitrogen ($\ce{N}$), oxygen ($\ce{O}$), and hydrogen ($\ce{H}$).
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what is the process of evaporation? when you get out of a swimming pool…
(6) Sweat is mostly water. When sweat appears on the skin, the water absorbs heat (energy) from the skin. This causes the water to evaporate, and the body feels cooler. (7) It wil…
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name horon w esrare class 3chem date 9/18/25 section 3 changes of state…
(3) Energy (4) The temperature at which a substance changes from a solid to a liquid; it is a physical property that depends on the composition of the substance and can be used to…
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what is the general ratio of protons to neutrons in stable isotopes of …
B. 1 : 1
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name aaronaconeslac class 3rd chem date 9/18/25 chapter 3 states of mat…
1. Energy 2. The water in the puddle evaporates. The water molecules gain energy, move faster, and change from a liquid state to a gaseous state (water vapor) and rise into the ai…
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what part of an atom is involved in chemical reactions? 250 words remai…
Electrons
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4. in the simulator, experiment by adding each type of particle to your…
4. Protons 5. No 6. Yes 7. Protons and neutrons 8. Yes 9. 2 10. 5 11. 8 12. It becomes a negatively charged ion
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what do the pair of symbols $_{92}^{235}u$ and $_{92}^{238}u$ represent…
C. isotopes
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which of these is the correct nuclear notation of the isotope oxygen - …
B. $^{15}_{8}O$
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5. how does the poems rhyme scheme contribute to the overall mood? the …
The consistent rhyming creates a calm and steady mood, reflecting the routine of daily life.
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water can travel up a glass tube against the force of gravity! this is …
Adhesion; Cohesion; Adhesion and cohesion; Gravitational
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1 how does the poems division into three stanzas contribute to its over…
Each stanza uses a different rhyme - scheme to contrast emotions.
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part 6. discussion and future work 1. a known characteristic of this pa…
1. Use a humidity - controlled chamber. 2. Different chemical compositions may affect paint properties. 3. Temperature, surface, and application method. 4. Optimal ratio, performa…
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4. there are 40 liters of helium in a balloon at a temperature of 100 k…
80 L ### 15.
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10) mark the following with p for pny. a. _p_ crumpled paper b. _c_ bur…
10) Physical changes (P): A, E, G; Chemical changes (C): B, F, D, H 11) Boiling Point, Density, Melting Point, Temperature 12) d. 15 g/mL 13) Homogeneous mixture: pure water, salt…
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lesson objective students will differentiate between physical and chemi…
Claim: I claim that a phase change is a physical change because the chemical identity of the substance remains the same during a phase change. Evidence: My evidence is that when a…
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18. kmt stands for______ kinetic muscular timing kinetic molecular theo…
B. Kinetic Molecular Theory ### 13.
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lesson objective students will be able to differentiate between physica…
Claim: physical Evidence: - My evidence is that when a melting happens, the substance is still the same substance chemically. - Another piece of evidence is when boiling occurs, n…
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11. if the pressure exerted by a gas at 25 degrees c in a volume of 0.0…
11. C. 0.0069 mol 8. C. 298
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multiple - choice question ______ deals with heated molecules moving aw…
C. convection
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name: date: physical and chemical properties worksheet **identify if th…
# Explicación paso a paso: ## Paso 1: Definir propiedades físicas y químicas Las propiedades físicas se pueden medir o observar sin que el material cambie su composición química. …
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1. where does the name atom come from? 2. what were daltons five postul…
1. The word "atom" comes from the Greek word "atomos" meaning indivisible. 2. - a. Elements are composed of atoms. - b. All atoms of a given element are identical. - c. Compounds …
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name warm up sept 18th be prepared for a quiz tomorrow (sept 19th frida…
$BaBr_2<AlBr_3<BaCl_2<AlCl_3$
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between the right and left hemispheres. what was gwen born without? 12.…
12. Decrease in neurotransmitters like acetylcholine. 13. Parasympathetic nervous system. 14. Thalamus. 15. Vision. 16. Serotonin. 17. Right post - central gyrus (parietal lobe). …
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12. saras grandfather has developed alzheimers disease. what can you te…
12. Widespread changes in neurotransmitters (e.g., reduced acetylcholine). 13. Parasympathetic nervous system. 14. Thalamus. 15. Vision (due to occipital lobe damage). 16. Seroton…
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complete the paragraph to explain why water is a polar molecule. in a m…
In a molecule of water, the oxygen atom shares **electrons** with each hydrogen atom. Oxygen also has **two nonbonding pairs of** electrons. Because valence electrons are more att…
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chemistry: a chemist looks up several unknown substances to determine t…
no
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question 2. classify each of the following as a homogeneous or heteroge…
(a) Homogeneous Mixture (b) Homogeneous Mixture (c) Heterogeneous Mixture (d) Heterogeneous Mixture
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xit ticket 7 (module 2 - lesson 5) question 1. what is the difference b…
A pure substance has a fixed and definite composition, either an element (made of one - type of atom) or a compound (made of two or more types of atoms chemically combined in a fi…
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additional chemical hazards training must be provided to employees: ann…
When new hazards are introduced into the workplace
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question 10. which of the following statements are true regarding the r…
Energy is always involved when physical or chemical changes occur. Heat can provide enough energy to cause both physical changes (such as melting) and chemical changes (such as th…
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to boost the performance of oil - absorbing resins, which are used to r…
A. For both toluene and trichloromethane, the BZMA - derived resin exhibited only modestly lower absorption capacity than the resin synthesized from β - cyclodextrin but higher ab…
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blandine courel and her colleagues analyzed pottery fragments from thir…
A. Across the Volga and Don basins, people had broadly similar access to the same terrestrial and aquatic animal resources.
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2. the yearly catch of fish from natural waters is a. increasing. b. ho…
2. b. holding constant or decreasing 3. d. ocean water 4. d. water is lost through evaporation 5. b. located in tidal areas 6. a. fish density 7. c. the more difficult the managem…
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your slide deck presentation is about renewable energy. what should you…
copying your full speaking notes verbatim
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in this experiment, you will change the temperature and particle size o…
How do temperature and particle size of an antacid tablet affect the rate of the reaction?
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what is a function of the integumentary system? (1 point) absorbs water…
forms blood clots
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question 3. some physical properties of two samples of iodine - 127 at …
B. states of matter
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each layer of earth has different physical and chemical properties. thi…
Composition of the layers
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match each description to the correct term. solid liquid gas matter tha…
Solid: Matter that has a definite shape and volume. Liquid: Matter that has a definite volume and takes the shape of its container. Gas: Matter that takes both the shape and volum…
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soft or nourishment. our present ways of living have, i think, been dis…
D. uncut 15. Since there is no chart provided, we cannot answer this question. 16.
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1. when a substance changes from a solid to a liquid, it is undergoing …
1. c. Melting 2. c. Condensation 3. d. Condensation 4. c. It remains constant
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21 true or false? taste is not a physical property of matter. a) false …
b) true
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acid rain is a dilute solution of acids that dissolve the calcium carbo…
Acid concentration affects reaction rate. Concentrated acids react faster. Statues with intricate carvings have larger surface - area exposed to acid rain, so they break down more…
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12. in which state does matter completely fill its closed container? a)…
12. b) Gas 14. b) Solid 20. d) Condensation 21. b) true 22. d) a lake
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reactant a can participate in both of these reactions: 1) a + b → c + d…
The activation energy of Reaction 1 is lower than that of Reaction 2.
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select the correct collision theory explanation for changing the rate o…
- Refrigerate food to keep it from spoiling: Particles collide less frequently (due to lower temperature). - Add inert water to a reaction solution: Particles collide less frequen…
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select the correct collision theory explanation for changing the rate o…
1. Refrigerating food: Decreases reaction rate by reducing collision frequency and energy. 2. Raising boiling point with a pressure - cooker: Increases reaction rate by increasing…
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select the correct collision theory explanation for changing the rate o…
1. Decrease reaction rate by lowering temperature (decreasing collision frequency). 2. Increase reaction rate by increasing temperature (increasing collision frequency). 3. Decrea…
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magnesium reacts with hydrochloric acid to form hydrogen gas and magnes…
using hot hydrochloric acid solution, using magnesium powder instead of a large piece of magnesium
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magnesium reacts with hydrochloric acid to form hydrogen gas and magnes…
using hot hydrochloric acid solution, using magnesium powder instead of a large piece of magnesium
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for the questions below determine if the particle that is described in …
5. Charge: no charge, Is this an atom or an ion?: atom 6. Charge: negative, Is this an atom or an ion?: ion 7. Charge: positive, Is this an atom or an ion?: ion 8. Charge: positiv…
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use the text to compare and contrast synthetic glue and natural glue. f…
Takes a long time to dry: Synthetic glue - □, Natural glue - ■ Hard to wash off: Synthetic glue - ■, Natural glue - □ Gets weaker with age: Synthetic glue - □, Natural glue - ■
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which of these is a common use for an erlenmeyer flask? it is used for …
It is used for swirling the contents during a reaction to help mixing.
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why are stirring rods normally made of glass? the glass protects the us…
The glass reduces the likelihood of the rod reacting with the liquid.
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what is the equipment marked with the arrow? graduated cylinder stirrin…
stirring rod
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what is the purpose of a funnel? it allows for catching and directing t…
It allows for catching and directing the flow of liquids.
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which of these is a common use for a graduated cylinder? for containing…
for making precise measurements
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how can a petri dish be used in chemistry? it allows for catching and d…
It is used for making different reactions visible in a wider space.
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what is the symbol for oxygen? ox og o oy
C. O
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what is the symbol for nitrogen? ni n nr nt
B. N
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what is the symbol for carbon? ca cr c cn
C. C
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what is the symbol for magnesium? m mg mn ma
B. Mg
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what is the symbol for fluorine? fl fr fn f
D. F
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chemistry drill - elements 1 what is the symbol for lithium? l lt li tl
C. Li
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building blocks can be used as an analogy for how compounds are formed.…
The model may oversimplify complex chemical interactions.
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which of these is a potential limitation of using this simulation to st…
It may oversimplify real - world conditions, making it harder to apply this understanding.