化学
化学反应、化学计量、分子结构与元素性质。
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part c - identify the incorrect practices in the lab. room and list dow…
1. Not wearing safety goggles. 2. Horse - playing and rough behavior. 3. Eating and drinking in the lab. 4. Not wearing lab coats.
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think about it: molecules and chemical equations how many atoms of carb…
How many atoms of carbon are in one methane molecule? 1 How many atoms of hydrogen are in one methane molecule? 4
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writing names writing names is also straightforward. you use the approp…
a. $CO_2$ b. $P_2S_3$ c. $SiO_2$ d. $N_2O$ e. $H_2O$ f. $Cl_2O$ g. $CS_2$ h. $Br_2$ i. $SO_3$ j. $CO$ k. $CCl_4$ l. $XeF_4$ m. $SO_2$ n. $Ne$ o. $N_2O_4$ p. $SiH_4$ q. $NO$ r. $IC…
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4. after you clean your work area, what should you do before leaving th…
4. Wash your hands. 5. No.
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read the following pages (104 - 108) and write a brief three - paragrap…
(No actual essay is provided as the task is to write an essay following the given guidelines. But the above is a summary of how to approach it.)
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vocab quiz: matter name witter core 1 word bank v.2 a. compound b. mixt…
1. C. Element 2. A. Compound 3. B. Mixture 4. H. Homogenous 5. G. Heterogenous 6. F. Proton 7. J. Electron 8. I. Neutron 9. E. 13 10. D. 27
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check your mastery of 2.4 2.4 focus on research: the case of the disemb…
Neither of the given options is correct.
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6. was dalton’s atomic theory accurate? why? (2 pts.)
No. Later discoveries of sub - atomic particles and isotopes showed its inaccuracies.
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question 4. a student prepared two mixtures, each in a labeled beaker. …
Heat the mixture 1 in a beaker over a Bunsen burner or hot plate. As the water is heated, it will evaporate, leaving the dissolved table - salt (NaCl) behind in the beaker. Use a …
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3) calculate the average atomic mass of lithium (li), which occurs ^6li…
$6.927$ amu
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question 3. given the diagram representing a process being used to sepa…
B. Chromatography
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13 question (2 points) provide the systematic name for the following io…
Part 1: potassium phosphate Part 2: calcium nitrate Part 3: chromium(II) phosphate
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diane draws a picture on a piece of paper and then folds it into a pape…
D. all of these
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question 2. at room temperature, a mixture of sand and water can be sep…
C. filtration
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question 1. equal amounts of ethanol and water are mixed at room temper…
Distillation.
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jolene wants to experiment with sugar cubes. which of the following cau…
1. B. crushing the sugar cube and dissolving it in water 2. B. the appearance of a substance changes but its identity does not.
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two solutions are added together and the new solution becomes hot. this…
1. d) a chemical change is taking place. 2. a) both chemical and physical
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a) a chemical has changed size. b) a chemical has changed to a differen…
1. None of the above options for the first part are chemical changes. They are physical changes (size, state, shape). The correct answer for what indicates a chemical change among…
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review the fourth paragraph. smart food perusing the food choices in ea…
The animals on nonorganic farms are given foods that contain pesticides, which are the source of diseases in people.; Experts think that when animals are treated with antibiotics,…
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1. un gas no tiene definida, y tampoco tiene de definida 2. la distanci…
# Breve Explicación: 1. En los gases, las partículas no tienen una distancia definida entre sí y no tienen fuerzas de atracción definidas, lo que les permite dispersarse y llenar …
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2. el tipo de sólido depende de la manera cómo las están dispuestas. a.…
a. Sólido cristalino b. Sólido amorfo C. 1. Volumen, forma 2. Forma 3. Mayor 4. Menores 5. Viscosidad 6. Cohesión 7. Tensión superficial 8. De atracción, viscosidad D. 1. Forma, v…
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ph measures the acidity of a substance, and is described by the equatio…
$pH = -\log(7.3\times 10^{-4})$
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which of the following scenarios best illustrates the difference betwee…
The volume of water in a beaker increases as more water is added, but the boiling point of the water remains the same.
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1) state two key purposes of john daltons atomic theory. 2) j.j. thomso…
1. To explain matter composition and chemical reactions. 2. Deflection of cathode rays by electric and magnetic fields. 3. Firing alpha - particles at a thin gold foil with a dete…
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question 10. describe the process you would use to determine whether a …
To determine if a substance is pure or a mixture, we can use physical separation techniques like evaporation and filtration and observe properties such as melting/boiling points. …
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which of the following characteristics are not typical of homogeneous m…
A. The presence of multiple phases or layers E. Variable composition depending on the location within the mixture
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elements are organized into families according to their physical and ch…
Alkali Metals - 1 valence electron: Hydrogen (H), Lithium (Li) Alkaline Earth Metals - 2 valence electrons: Calcium (Ca), Magnesium (Mg) Boron Family - 3 valence electrons: Boron …
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question 8. match each example to its correct classification. a) air b)…
a) Homogeneous Mixture b) Homogeneous Mixture c) Element d) Element e) Heterogeneous Mixture f) Compound g) Compound h) Homogeneous Mixture
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question 7. given the particle diagram: key o = atom of an element ● = …
A. A compound
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homework 7 - 09/19/2025 question 6. which statement describes a mixture…
It is heterogeneous, and its components are in different phases.
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question 5. a pure substance is classified as either a(n) or a(n)
element, compound
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question 4. is the following statement true or false? if the statement …
False. A homogeneous mixture is one that has a completely uniform composition.
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8. what type of element does the neon green color indicate? list the el…
8. Cannot be determined without more context. 9. 5 elements: F, Cl, Br, I, At 10. a. Salt - former. b. Hydrogen - halide molecule. 11. Alkaline - earth metals 12. Metalloid family…
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question 3. classify the following examples as a homogeneous or heterog…
a) Homogeneous Mixture b) Heterogeneous Mixture c) Homogeneous Mixture d) Homogeneous Mixture e) Heterogeneous Mixture f) Heterogeneous Mixture g) Heterogeneous Mixture h) Homogen…
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pure substance mixture element compound homogeneous mixture heterogeneo…
- Pure substance: A sample of matter, either a single element or a single compound, that has definite chemical and physical properties. - Mixture: A physical blend of two or more …
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batteries are filled with: ○ a. ascorbic acid. ○ b. sulfuric acid. ○ c.…
B. Sulfuric acid
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1. below is a flowchart representing the classification of matter. comp…
From left - to - right, top - to - bottom: Heterogeneous Mixture, Homogeneous Mixture, Element, Compound
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6) what was the most surprising observation from rutherfords gold foil …
6. A small fraction of alpha particles were deflected at large angles. 7. A small, dense, positively - charged nucleus at the center with electrons orbiting around it. 8. b. Ruthe…
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four beakers and their contents are listed below. | beaker | mixture | …
D. Beaker 3
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select the independent clause. after a lightning bolt passes through th…
the compression and subsequent rapid expansion of the air molecules produces the booming sound of thunder
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1) john daltons atomic theory proposed that all elements are composed o…
1. atoms 2. properties 3. electrons 4. c) Plum pudding model 5. alpha particles
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9/19/25 and 9/22/25 answer in complete sentences or complete thought 1.…
1. There are 7 rows on the periodic table. 2. There are 18 columns on the periodic table. 3. The periodic table is arranged by increasing atomic number. 4. The maximum number of e…
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read the rough - draft paragraph. (1) many people experience a sense of…
C. 3
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in the laboratory, giselle has a mixture of water and rubbing alcohol. …
B. physical change
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pablo is making a solution. he puts 1 g of sugar into 1 l of water. whi…
B. a physical change
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a chemical change of matter takes place when one or more substances cha…
Vinegar bubbles when baking soda is added.
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a chemical change of matter takes place when one or more substances cha…
Vinegar bubbles when baking soda is added.
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there are several differences between chemical and physical changes. wh…
D. A chemical change can produce warmth.
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when paper is burned, the mass of the remaining ash is less than the ma…
B. Some of the mass is lost as it escapes in smoke.
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chemical changes result in new substances, but physical changes do not.…
A loaf of bread being sliced into pieces.
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rita wants to make some toast for breakfast. she puts a slice of bread …
B. added warmth
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what should a scientist do if they want to speed up the chemical reacti…
Increase the temperature of the substance
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increasing the temperature during a chemical reaction will decrease the…
True
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4.1 - 4.2 review read this: for this review you will need: your journal…
1. See filled - in chart above. 2. Positive, determined by number of protons. 3. In the nucleus; protons and neutrons in nucleus have significant mass compared to electrons. 4. Pr…
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the passage below discusses some of the steps of an engineering - desig…
Kari combines several different chemicals to create a test batch of the new window cleaner.
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study guide chapter 6 section 1: atoms, elements, and compounds in your…
1. electron 2. energy level 3. neutron 4. nucleus 5. proton 6. false, symbol 7. false, groups 8. true 9. true 10. false, half - life 11. false, compound 12. false, ionic bonds
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a nitride ion has 7 protons, 8 neutrons, and 10 electrons. what is the …
-3
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which element has 16 protons in its nucleus? neon oxygen sodium sulfur
D. sulfur
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in which block of the periodic table is uranium (u) found? s block d bl…
D. f block
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the mass number of fe²⁺ is 56. how many neutrons are there in a single …
B. 30
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boron occurs naturally as two isotopes. what is the difference between …
They have different numbers of neutrons and different mass numbers.
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in which block of the periodic table is chromium (cr) found? o s block …
B. d block
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the table below gives the numbers of protons, electrons, and neutrons i…
D. Atom 4
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it is easier to determine the electron configurations for the p - block…
B. their electrons are assigned to s and p orbitals only.
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which statement best describes john daltons use of creativity in his wo…
He reinterpreted and retested Joseph Proust's results.
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esophagus: stomach: small intestine: large intestine: rectum: click on:…
22. A collection of glands that produce and secrete hormones directly into the bloodstream to regulate bodily functions. 23. Chemical messengers produced by endocrine glands that …
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on: digestive system click on the diagram and describe each part of the…
The mouth is the initial part of the digestive system. It mechanically breaks down food by chewing and saliva starts the chemical digestion of carbohydrates while also moistening …
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question 4 of 5 read the sentence from paragraph 2. all the next day th…
B. attempt
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read the excerpts from lizzie bright and the buckminster boy. excerpt 1…
the only one for all the island's students.
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if the temperature of a container of gas remains constant, how could th…
The number of gas molecules in the container increases.
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question 7 1 pts what is the name given to the figure in which a line b…
Question 7: a paired orbital Question 8: Pauli
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three quantum numbers for an electron in a hydrogen atom in a certain s…
Question 1: A. 4p Question 2: A. 18 Question 3: C. 15
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three quantum numbers for an electron in a hydrogen atom in a certain s…
# Explanation: ## Step1: Identify orbital type from quantum numbers The principal quantum number $n = 4$ indicates the energy level. The angular - momentum quantum number $\ell=1$…
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what block and what period are associated with the element sulfur, s? t…
1. the p block and the third period. 2. the d block and the fifth period. 3. 5 d; 5
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good news: dont worry, we will be going over this information in much m…
A. the periodic table
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the really good news is that when we are all through with the math for …
electrons repel each other.
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an orbital is described by combining the n quantum number with the $l$ …
1. True 2. C. s
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the third type of chemical bonding, metallic bonding, occurs between me…
- Valence electrons move freely throughout a metal. - Metallic bonding occurs between metal atoms.
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consider the lewis dot structures of lithium and fluorine atoms. li ·f:…
$[\text{Li}]^{+}[\ddot{\text{F}}:]^{-}$ (the first option in the given choices)
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6 of 13 which of the following is an example of the best way to manage …
"To sum up Megan's question, she's asking whether trees can cure pollution."
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ionic compounds can be represented by bohr model diagrams and lewis dot…
Valence electrons are shown in the Bohr model of a sodium cation. A sodium cation has zero valence electrons. Both the Bohr model and the Lewis dot structure represent an ionic bo…
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ammonia (nh₃) is a covalent compound. the nitrogen atom shares a pair o…
The first and fourth Lewis - dot structures are correct as they show the nitrogen atom bonded to three hydrogen atoms and have a lone - pair of electrons on the nitrogen. The seco…
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covalent compounds can be represented by bohr model diagrams and lewis …
A. A chlorine molecule has 14 total valence electrons. D. There are two bonding electrons in a chlorine molecule.
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reset the simulation (see directions between questions 3 and 4 if you n…
1. Sodium 2. The atomic radius decreases from left to right within the same period.
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choose the elements magnesium (mg) and strontium (sr) from period 2. lo…
First question: B. Strontium Second question: A. Boron
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which element appears larger in the side - by - side comparison? (see p…
1. Cesium 2. No answer (due to lack of lab - investigation data)
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the \size\ of the atom: generally increases from top to bottom within a…
For the first description "The 'size' of the atom...": Atomic Radius For the second description "The amount of energy needed to remove an electron from an atom...": Ionization Ene…
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compare the bohr model and lewis dot structure of an oxygen atom. the l…
All of the provided Lewis - dot structures for phosphorus are correct.
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atoms tend to be stable when they have a full valence shell. most main …
2
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atoms tend to be stable when they have a full valence shell. most main …
An oxygen atom is less stable than a neon atom. An oxygen atom will gain electrons to fill its valence shell.
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atoms tend to be stable when they have a full valence shell. most main …
An oxygen atom is larger than a neon atom. An oxygen atom will increase its electron count by 2 to fill its valence shell.
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the number of valence electrons that an atom has impacts its stability.…
Helium has 2 valence electrons, neon has 8 valence electrons, and argon has 8 valence electrons. All three noble gases have a full valence shell.
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there are three types of chemical bonds: covalent, ionic, and metallic.…
A. A chlorine atom has seven valence electrons. B. Valence electrons can be shared between atoms or transferred from one atom to the other. D. Atoms combine by forming metallic, c…
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sodium (na) is a gray, metallic solid that reacts strongly with water. …
B. When atoms of two different elements bond, they form a new compound with unique properties. D. In table salt, sodium and chlorine are held together by chemical bonds.
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periodic table worksheet 1. tell which element is located in the follow…
a. Zirconium (Zr) b. Beryllium (Be) c. Tungsten (W) d. Helium (He) e. Tin (Sn) f. Zinc (Zn) g. Francium (Fr) h. Polonium (Po) i. Chlorine (Cl) j. Silver (Ag) k. Vanadium (V) l. Pl…
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how do we classify matter? answer in 2 - 4 sentences, including the wor…
Matter can be classified as either a pure substance or a mixture. A pure substance can be an element (made of one - type of atom) or a compound (different atoms bonded).
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3. vertical columns on the periodic table are called 4. horizontal rows…
3. Groups 4. Periods 5. Atomic 6. Mass 7. Ductility 8. Malleability 9. Transition metals 10. Alkali metals 11. Alkaline - earth metals 12. Noble gases 13. Halogens 14. 1 15. 17 16…
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multiple - choice question true or false: water can be separated into d…
False
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answer the following questions. choose the best answer. why should you …
Using a variety of sentence structures helps a piece of writing to be more interesting and smooth and less monotonous. Complex sentences help to show the connections among ideas a…
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which of the following is true? this mixture only contains compounds. t…
It is impossible to determine which option is true without more information about the mixture.