化學
化學反應、化學計量、分子結構與元素性質。
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use the periodic table to answer the question. how many valence electro…
seven
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why do atoms exchange or share electrons during bonding? (1 point) to a…
to obtain a full outer electron shell
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patterns of properties quick check what are valence electrons? (1 point…
the electrons in an atom's outermost energy level
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7. which answer best support your answer to part a? a. “one of the main…
7. B. "The chemicals that are released during fight - or - flight can work like glue to build strong memories ('flashbulb memories') of scary experiences...you'll never forget" (4…
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patterns of properties quick check which feature defines a neutral atom…
the number of electrons equal to the number of protons
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ethan heard that a person who is having a heart attack should chew an a…
- Does a sugar cube dissolve faster in water if the water is stirred with a spoon? - Does crushing a sugar cube make it dissolve faster in tap water?
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devin is preparing a glass of salt water for a mouthwash. as the salt d…
Does dissolving salt in water lower the water's temperature more than dissolving sugar in water does? Does dissolving a larger amount of salt in water lower the water's temperatur…
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ben is mixing kitchen ingredients with his little brother. when ben add…
Does baking soda cause a bigger temperature change when mixed into a bowl of vinegar or into a bowl of water? Does baking soda bubble more when mixed into tap water or into carbon…
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tara is making rock candy. she wonders what factors affect how large th…
All of the above questions can be investigated.
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1. the addicting substance when you smoke or vape is called: a) carbon …
1. c) Nicotine 2. b) Heart 3. c) Cancer 4. a) Tar 5. b) Oxygen 6. c) Aerosol 7. a) Diacetyl
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4. the sticky substance caused by cigarette smoke that makes a) tar b) …
5. b) Oxygen 6. c) Aerosol
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jon is using a wet rag to wipe down the countertops in his kitchen. he …
Does tap water heated on a hot plate dissolve sugar faster than tap water chilled in a refrigerator does? Does tap water dissolve sugar faster when it is stirred with a spoon?
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which electrons participate in chemical bonding? the innermost electron…
valence electrons
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atomic theory timeline questions and rubric please choose the correct a…
1. b) Thomson 2. a) nucleus 3. a) Dalton 4. d) Bohr 5. c) indivisible 6. a) Aristotle 7. d) most of the atom is empty 8. c) Rutherford
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what can affect the properties of a substance? neither the arrangement …
the arrangement and types of atoms
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how do an ionic bond and a covalent bond differ? a covalent bond is an …
An ionic bond is an attraction between oppositely charged ions. A covalent bond is a sharing of electrons between atoms.
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what is the definition of a covalent bond? o a bond between two atoms o…
a bond between two atoms
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an ionic bond occurs between what particles? two negative ions two neut…
a positive and negative ion
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the list shows characteristics of an unknown substance. - the substance…
(There is no option text provided for the other options, but if we assume the correct diagram is one with all the same type of particles, we would choose the diagram that meets th…
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the passage below describes an experiment. in science class, jerry lear…
an independent variable
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the passage below describes an experiment. in chemistry class, cooper l…
a dependent variable
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the passage below describes an experiment. leo works at a candy store a…
an independent variable
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while watching tv, zack saw an advertisement for a water softener. the …
a dependent variable
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a paper clip floating on water. as tom used detergent to wash olive oil…
independent variable: the number of drops of detergent added to the water dependent variable: the number of paper clips that floated
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where does the energy come from to excite the electrons to a higher ene…
First question: its in the chemical bonds Second question: No, the colors are characteristic of the substance's elements
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where are the labs fire extinguishers? in the cabinet in the back of th…
C. Near the chemical storage room.
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when do you need to wear safety goggles? (circle all that apply.) when …
When the teacher instructs me to do so. When handling objects that may break, expand, or endanger my eyes in someway. When heat or chemicals are used.
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scientists used to believe that chemical reactions fueled the sun. why …
Scientists once thought chemical reactions fueled the young sun. We now think nuclear fusion reactions in the sun's core are responsible for the energy it releases because chemica…
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using the information from this experiment, scientists determined that …
Text Chunk 3: Experiments led to the revision of Thomson's atomic model, discovery of protons and neutrons, and understanding of atomic structure with a nucleus and electrons in e…
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how is fusion different from a simple chemical reaction? (1 point) ener…
Energy is released in a fusion reaction, but it is absorbed in a chemical reaction.
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during the early 1800s, these professionals regularly appeared in court…
forensic science
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determining the composition of an atom 1. calculate the number of proto…
Number of protons: 5, Number of neutrons: 6, Number of electrons: 5
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what does hydrophobic mean? loves water hates/dislikes water will disso…
B. hates/dislikes water
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which statement best describes the difference between a physical change…
A physical change is a change from one state of matter to another; a chemical change results in a new substance formed.
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4. identify the reaction type shown here. nacl + agno₃ → nano₃ + agcl s…
Double Replacement
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1. identify the type of reaction shown here: s + cl₂ → scl₄ show the ty…
Combination
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atoms, elements and compounds student worksheet compound name\tchemical…
The completed table as shown above.
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how do scientists determine the number of neutrons in an isotope of an …
They subtract the atomic number from the atomic mass.
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2. create the generalized reaction for each reaction type by dragging s…
Combination: $A + B ightarrow AB$ Decomposition: $AB ightarrow A + B$ Single Replacement: $A+BC ightarrow AC + B$ Double Replacement: $AB + CD ightarrow AD+CB$ Combustion: $C_xH_y…
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which subatomic particle has a positive charge? all particles proton el…
proton
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summary in this section, we summarize the five reaction types. 1. summa…
Combination: Two simple substances, often elements, react to form a single compound. Decomposition: A single compound reacts to form two or more simpler substances. Single Replace…
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unit 7 \physical interaction\ test the function of an electric motor is…
electrical energy into mechanical energy
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unit 7 \physical interaction\ test the function of a generator is the c…
mechanical energy into electrical energy.
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4. balance the equation for the combustion of ethanol by dragging the c…
1. $C_{25}H_{52}$, 38. $O_2$, 25. $CO_2$, 26. $H_2O$
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2. in combustion reactions, a substance reacts with oxygen gas to produ…
$C_{25}H_{52}+O_2 ightarrow CO_2 + H_2O$
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1. observe the combustion of a candle. identify each substance in the t…
| Substance | Reactant or Product? | Evidence | |--|--|--| | CO₂ | Product | The probe reading shows the quantity of this substance increases as the candle burns. | | O₂ | Reactan…
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two versions of an element with different numbers of neutrons are calle…
isotopes.
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1. observe the combustion of a candle. identify each substance in the t…
A. Product B. Lime - water turns milky when exposed to gas from burning candle. C. Reactant D. Flame goes out in a closed container due to oxygen consumption. E. Product F. Water …
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pregunta 1 - 27 a firefly uses specialized muscles to draw oxygen into …
C. Specifically
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passage: in nature nothing exists alone... the contamination of the env…
B. Cite specific ecological case studies that demonstrate cascading effects of chemical use.
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6. build the net ionic equation for the reaction that produces the lead…
$Pb^{2+}+2I^- ightarrow PbI_2$
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5. balance the double replacement reaction by dragging the correct coef…
5. Coefficients: 1, 2, 1, 2 6. $Pb^{2+}(aq)+2I^{-}(aq)\to PbI_2(s)$
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how did the concerns depicted in this cartoon affect the food industry?…
The federal government regulated the food industry in order to protect the health of the public.
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pregunta 1 - 22 while researching a topic, a student has taken the foll…
# Breve explicación: El objetivo de la investigación de Terada era determinar si parte del oxígeno de la Luna provenía de la Tierra. Las otras opciones se centran más en los métod…
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the surface tension of the alcohol propanol in air has a value of 23.70…
A. Propanol will have a lower boiling point than water because the forces between the molecules are smaller. C. Propanol will have a flatter meniscus than water because the forces…
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when he carried out his experiment, nathan found that he had three smal…
A. No, because the area exposed to the surface will be different, changing the rate of boiling.
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we use the solubility rules to determine the precipitate. the precipita…
The insoluble product is $\text{PbI}_2$. The balanced equation with states is $\text{Pb}(\text{NO}_3)_2(aq)+2\text{KI}(aq) ightarrow\text{PbI}_2(s) + 2\text{KNO}_3(aq)$
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clarisse had three substances. a white substance was waxy and malleable…
B. The white substance was molecular. C. The red substance was ionic.
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the double - replacement reaction is between aqueous lead(ii) nitrate a…
\(KNO_3\), \(PbI_2\)
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how does the strength of the forces that hold the basic particles of a …
B. Stronger forces between particles means the substance boils at a higher temperature.
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2. in the double replacement reaction between aqueous lead(ii) nitrate …
Yellow
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which statement describes the relationship between bonding and surface …
B. The more hydrogen bonds a molecule can make, the higher the surface tension.
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which two options describe physical properties of matter? a. a substanc…
B. A substance's ability to conduct electricity C. A substance's resistance to flow
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which type of force is the weakest? a. van der waals forces b. hydrogen…
A. Van der Waals forces
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which statement accurately describes malleability? a. a material with r…
A. A material with relatively weak bonds between its particles can be shaped into a thin sheet.
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b. balance the equation for the reaction between potassium iodide and c…
$2KI + Cl_2 ightarrow2KCl+I_2$
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a copper wire is left outside on the ground for several weeks. which st…
B. It becomes tarnished.
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why is an ice cube less dense than liquid water? a. molecules in ice ar…
A. Molecules in ice are more spread out than molecules in liquid water.
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which statement compares the attractive forces that hold particles toge…
C. Hydrogen bonding and Van der Waals forces are weakly attractive; ionic and polar covalent bonds are strongly attractive.
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which statement describes a physical property related to the particles …
C. Salt crystals are hard and brittle because they are made up of atoms that combine by ionic bonding.
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why do nonpolar compounds tend to have lower melting points and boiling…
D. Nonpolar molecules only have Van der Waals forces between them.
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what is the name of large molecules that are made up of many small subu…
Polymer, Macromolecule
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4. observe the reaction between potassium chloride and iodine. kcl + i₂…
The solution remains purple.
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3. observe the reaction between potassium iodide and chlorine. ki + cl₂…
The solution turns from clear to purple.
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10. we have observed that zinc is capable of replacing lead in a single…
$\text{Pb(NO}_3)_2(aq)+\text{Zn}(s) ightarrow\text{Zn(NO}_3)_2(aq)+\text{Pb}(s)$
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10. we have observed that zinc is capable of replacing lead in a single…
$Pb(NO_3)_2(aq)+Zn(s) ightarrow Zn(NO_3)_2(aq) + Pb(s)$
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which statement is the best description of a chemical reaction? the com…
forming or breaking bonds
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which statement describes an endothermic reaction? o energy is created …
Energy is absorbed by the reaction.
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which statement accurately describes the products of a reaction? o subs…
new substances that are present at the end of a reaction
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what has occurred if an increase in temperature accompanies a reaction?…
Energy was released.
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which evidence is an indication that a chemical reaction has occurred? …
formation of a precipitate
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electronic cigarettes (also called electronic nicotine delivery systems…
Neither e - cigarettes nor traditional cigarettes should be used during pregnancy.
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5. build the chemical equation for the single replacement reaction betw…
$2\text{AgNO}_3(aq)+\text{Cu}(s) ightarrow\text{Cu(NO}_3)_2(aq) + 2\text{Ag}(s)$
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4. observe the particle animation of the copper and silver nitrate reac…
$Cu(NO_3)_2$
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question 12 one place to learn the proper ppe to use when handling haza…
the product label
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3. we begin by studying a single replacement reaction in which a metal …
The silver nitrate solution is colorless, while the resulting solution with copper(II) ion solution is blue.
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choose the correct answer. which of these has the least heat? gaseous f…
solid form of CO2
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in single - replacement reactions, a single element replaces a similar …
Circles represent elements (metals or non - metals in single - replacement reactions), squares represent non - metals in single - replacement reactions.
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1. in single - replacement reactions, a single element replaces a simil…
Circles represent elements. Squares represent compounds.
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answer all questions. use complete sentences true/false questions 1. th…
False ## b.
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2. the decomposition of water can be accomplished when electricity is a…
Gas 1 is hydrogen
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the chemical energy in your food is transformed into what type of energ…
C. mechanical
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the chemical energy in your food is transformed into what type of energ…
kinetic
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4. build the chemical equation for the decomposition of water via elect…
$2H_2O\xrightarrow{electrolysis}2H_2 + O_2$
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when a person pushes a large load up an inclined plane, where does the …
Chemical energy
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which of the following can be considered chemical energy? a basketball …
a battery
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henry is visiting australia from germany and wants to buy 750 millilite…
28.80 EUR per liter
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3. observe and listen to the results of the splint test for gas 2. iden…
There is not enough information in the question to determine the answer among the options. But if we consider the characteristic reactions of these gases with a splint: - If the g…
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2. the decomposition of water can be accomplished when electricity is a…
Gas 1 is hydrogen
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the chemical energy in your food is transformed into what type of energ…
B. mechanical