Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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swyk: bonding and molecular properti which of the following compounds w…
C. \(CCl_4\)
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______ bonds are formed when electrons are transferred between elements…
1. Ionic 2. Metal 3. Positive 4. Cation 5. Nonmetal 6. Negative 7. Anion 8. Opposite
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 \text{F}_2(\text{g}) + \text{O}_2(\text{g}) ightarrow 2 \text{OF}_2(\text{g})\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \( 2 \text{ F}_2(\text{g}) + \text{ O}_2(\text{g}) ightarrow 2 \text{ OF}_2(\text{g}) \)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \( \ce{2 F2(g) + O2(g) → 2 OF2(g)} \)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 \text{F}_2(\text{g}) + \text{O}_2(\text{g}) ightarrow 2 \text{OF}_2(\text{g})\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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which forms of energy are observed as a candle at rest quietly burns? s…
b. thermal, c. chemical, d. electromagnetic radiation
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which forms of energy are observed as a candle at rest quietly burns? s…
b. thermal, c. chemical, d. electromagnetic radiation
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which form of energy is exemplified by the motion of wheels on a bicycl…
b. mechanical
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ere are four sketches below. the first sketch shows a sample of substan…
a physical change ### Change 2:
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question 1 (3 points) a dermatologist prescribes drysol as a treatment …
$17.86\%$ (w/v) ### Question 2
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13. the fuel tank of an airplane has a device that measures the fuel’s …
b. the molecules started moving slower.
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12. a scientist has two substances in her lab: a pink substance and a g…
a. weaker attraction between its molecules than the green substance. Its molecules now move away from each other
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9. what happens to molecules when their kinetic energy decreases? a the…
a. They move slower.
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a student is investigating a sweet food and a jar containing a sour foo…
d. The sour food changed because the molecules were able to move fast enough to overcome the attraction between them. Its molecules now move in place.
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students designed an experiment to test how the movement of molecules i…
A. The substance’s molecules slowed down and the substance changed into a liquid.
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5. a scientist has a container with a substance inside. at first, the m…
b. Before, the substance was a gas. Later, it was a liquid.
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3 divers found two substances on the bottom of the ocean. at room tempe…
b. weaker attraction between its molecules than Substance 2. Its molecules now move around each other.
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elements in the same column: - have similar ________ _______________ - …
### Part 1: Elements in the same column #### Explanation: Elements in the same column (group) of the periodic table have similar **chemical properties**, the same number of **vale…
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following problems are made for the first 18 elements in the periodic t…
To solve the problem of filling the periodic table with elements based on the clues, we analyze each clue step - by - step: ### Step 1: Analyze Clue 1 The clue says "La has 5 vale…
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period: * __________ on ______________ ______________ * tells _________…
To solve this fill - in - the - blank problem about the periodic table (a key concept in Chemistry, a subfield of Natural Science), we analyze each section: ### Period Section - *…
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dmitri mendeleev: - arranged elements by ______ ______ ______. - predic…
s for the fill - in - the - blanks: #### Dmitri Mendeleev: - arranged elements by $\boldsymbol{\text{increasing atomic mass}}$. - predicted $\boldsymbol{\text{properties}}$ of mis…
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modern periodic law: properties of elements when elements are arranged …
Properties of elements \underline{are periodic functions} when elements are arranged by \underline{increasing atomic number}.
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what changes cause volcanism, chemical weathering of rocks and the buri…
Changes in carbon dioxide
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dmitri mendeleev: - arranged elements by ____________ ____________ ____…
### Dmitri Mendeleev: - arranged elements by **increasing atomic mass**. - predicted **properties** of missing **elements**. ### Henry Moseley: - discovered that each **element** …
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fictitious symbols are used for the first 18 elements in the periodic t…
To solve for each fictitious element, we analyze each clue: ### Clue 4: X has one proton - An element with 1 proton is hydrogen (atomic number 1). So X is in group 1, period 1 (to…
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what is the main reason for changing the use of pesticides over time? t…
environmental and health concerns
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in what order should chemicals be used in ipm? only acceptable pest con…
last resort for pest control
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kinetic molecular theory this theory describes all matter as being comp…
### Cold Gas Particle Diagram Description: - Draw a square (container). Inside, place small circles (particles) that are relatively closer to each other (but still not touching, m…
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which of these persists (lasts the longest in the environment) after be…
B. DDT pesticide
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which of these terms describes a pesticide that does not break down eas…
A. persistent
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which pesticides are the most persistent? botanicals organophosphates c…
D. chlorinated hydrocarbons
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questions: 1. explain why the alcohol level in a thermometer rises when…
The alcohol level rises because: 1. Initially, alcohol particles in the thermometer move with some kinetic energy. 2. When placed in warmer fluid, heat is transferred to alcohol p…
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what term is used to describe an increased concentration of toxic chemi…
The correct option is: biomagnification (the term describing increased toxic chemical concentration up the food chain). The other option, biodegrading, refers to breakdown of subs…
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which pesticides are the most persistent? botanicals chlorinated hydroc…
Chlorinated hydrocarbons
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what is ddt? a popular pesticide used during world wars a pyrotechnic i…
A. a popular pesticide used during world wars
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which were popular chemical compounds that were found to be effective i…
C. pyrethrum and rotenone
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please note: leaving this page before submitting your assessment will r…
a) Development of tiny holes or weakening of the rubber
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what separation technique is illustrated in the picture? filtration dis…
filtration
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water and alcohol are two liquids that mix completely but can be separa…
boiling point
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which of these is an example of a physical property? tin has a density …
A. Tin has a density of \( 7.28 \, \text{g/cm}^3 \).
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the 14.7 g sample of graphite takes up a volume of 6.6 cm³. what is the…
$2.2$
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a graduated cylinder has 8.0 ml of water initially. a piece of graphite…
\(6.6\)
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convert 493.46 k to °c. ? °c
\(220.31\)
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use the drop-down menus to select the correct structural elements. a gr…
meter
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use the drop-down menus to select the correct structural elements. a gr…
rhyme scheme ### For the fourth blank (Patterns of stressed and unstressed syllables crea...): (Note: The original sentence seems cut off, but assuming it's about what patterns of…
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use the drop-down menus to select the correct structural elements. a gr…
First dropdown (group of lines): stanza Third dropdown (pattern of rhyming words): rhyme scheme Fourth dropdown (patterns of stressed and unstressed): meter (Note: For the second …
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ph = 2.52 express your answer using two significant figures. oh⁻ = m
\( 3.3\times 10^{-12} \)
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ph = 13.68 express your answer using two significant figures. oh⁻ = m s…
s: - For pH = 13.68: \( \boldsymbol{0.48} \) M (or \( 4.8 \times 10^{-1} \) M, but 0.48 is simpler here) - For pH = 8.39: \( \boldsymbol{2.5 \times 10^{-6}} \) M
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ph = 1.72 express your answer using two significant figures. oh⁻ = .48 …
\( 5.2 \times 10^{-13} \) (or \( 5.2e - 13 \)) M
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ph=1.72 express your answer using two significant figures. oh⁻ = m subm…
\( 5.2\times 10^{-13} \) ### Part B
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ph = 8.43 express your answer using two significant figures. h₃o⁺ = m s…
\(3.7\times10^{-9}\) M ### For pH = 12.82:
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ph = 3.98 express your answer using two significant figures. h₃o⁺ = m s…
\(1.0\times 10^{-4}\) (Wait, no, earlier mistake. Wait, \(10^{-3.98}\): let's calculate it as \(10^{-3.98}=e^{-3.98\ln(10)}\). \(\ln(10)\approx2.302585\), so \(-3.98\times2.302585…
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module 8: homework assignment - chapter 14 exercise 14.74 - enhanced - …
$\boxed{5.5\times10^{-2}}$ (or $0.055$)
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ph = 1.26 express your answer using two significant figures. h₃o⁺ = m s…
$5.5\times 10^{-2}$ M ### Part B
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not all drugs are considered medicines because ______. a. they are chem…
C. medicines are used to cure, treat, and prevent diseases
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2. what makes something inorganic? * it usually contains carbon and hyd…
D. It does not usually contain Carbon and Hydrogen
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a scientist is determining the mass of 38,000 molecules of oxygen. use …
\(2.0\times 10^{-18}\)
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a scientist is determining the mass of 38,000 molecules of oxygen. use …
2
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what was the essential characteristic of jackson pollock’s autumn rhyth…
A. application of paint in an organic and spontaneous manner
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question 4 1 pts h₂o select select polar molecule nonpolar molecule que…
polar molecule ### Question 5
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question 1 1 pts cbr₄ select select polar molecule nonpolar molecule qu…
nonpolar molecule ### Question 2 (Assuming the options are related to polarity or other molecular properties, but since options aren't provided, we'll focus on pyramidal geometry.…
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question 10 of 10 which of these uses ethos? a. yum organics has been p…
A. Yum Organics has been providing well - rounded organic lunches to schools on the West Coast for more than 15 years.
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question 20 (1 point) isotopes of an element have nuclei with the same …
A. the same number of protons, but different numbers of neutrons.
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question 18 (1 point) the atomic number and mass number for calcium 39 …
20 (corresponding to the option with 20, e.g., if the option is C. 20, then the answer is C. 20)
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which of these substances is a compound? chlorine uranium nitrogen wate…
Water (the option "Water") ### Second Question (Is water an example of a solute or solvent?)
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ocean water is a solution made of salt and water. what is the solvent i…
A. water ### Second Question (Definition of Atom)
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how many valence electrons are in an atom of argon? 8 40 17 18 question…
A. 8 ### Second Question (Sulfur's Outer - Most Ring Electrons)
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question 9 what is true about the position of any nonmetal in the perio…
C. It is to the right of the zigzag line. ### Question 10
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question 7 the periodic table consists of ______ periods. question 8 wh…
7 ### Question 8
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question 6 the rows in the periodic table are called ______.
periods
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to create a portfolio of work, this artist would do all of the followin…
D. include only a few images of the same type of drawing to show dedication to craft
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date: name(s): 5. hydrogen cyanide has the chemical formula hcn. the co…
$4.95$ (no units for pH, but as per the problem's request for answer + units, since pH is dimensionless, we can write $4.95$ (pH is unitless, but if we consider the problem's note…
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which element did this artist use most to emphasize her original creati…
B. color
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how are art and conservation science connected in this sculpture? (1 po…
A. The artist was repurposing materials to create art
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look at the following illustration of an early american settler. it wou…
the color scheme used
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the reaction between ammonium nitrate and water absorbs heat from the s…
To solve this, we first recall the definitions: - **Endothermic Reaction**: Absorbs heat from the surroundings (system gets cold, surroundings may cool). - **Exothermic Reaction**…
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drag each number to the correct location on the equation. each number c…
The balanced equation is \( \boldsymbol{2}\text{KClO}_3 ightarrow \boldsymbol{2}\text{KCl} + \boldsymbol{3}\text{O}_2 \)
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select all the correct answers. in this reaction, how does the rate of …
C. It increases with a decrease in the concentration of \( H_2(g) \) D. It decreases with an increase in the concentration of \( S_2(g) \) E. It decreases with increase in the con…
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given the following melting point data, are there any generalizations y…
A general trend is that many metals (e.g., Aluminum, Copper, Magnesium, Zinc) have relatively high melting points (420 - 1063°C) compared to typical non - metals (e.g., Iodine, Su…
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f. what human activity uses the most water worldwide? g. what human act…
Agriculture (including irrigation, livestock watering, etc.) ### G.
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activity: the water cycle get the gizmo ready: - select the simulation …
To answer these questions, we refer to typical knowledge about the water cycle (from the Gizmo simulation or standard Earth science resources): ### 1. Parts of the Water Cycle (Cy…
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use the equation for the formation of water to answer the question. 2h₂…
B. No, it does not because the number and mass of atoms are conserved even though the number of molecules is not.
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methane (ch₄) and oxygen (o₂) combine to make carbon dioxide (co₂) and …
two (the option corresponding to two oxygen molecules)
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which statement accurately describes what happens in a reaction when re…
Reactant bonds break and atoms rearrange to form new product combinations
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hydrogen ($ce{h_2}$) and oxygen ($ce{o_2}$) combine to make water ($ce{…
six (corresponding to the option with "six" as the text, e.g., if the option is labeled as, say, B. six, then B. six)
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use the chemical equation to answer the question. 2o₂ + ch₄ → ?h₂o + co…
A. two
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which example is a closed system? (1 point) ○ a sealed jar of salad dre…
a sealed jar of salad dressing
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in a chemical reaction, two molecules are rearranged to produce two new…
20 g (corresponding to the option with "20 g")
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which parts must be balanced in a chemical equation? (1 point) numbers …
A. numbers of reactant and product atoms
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balanced chemical equations quick check which statement best describes …
A. Matter cannot be created or destroyed in a chemical reaction
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a region of most probable electron location in an atom is called a nucl…
C. orbital ring
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50.0% of the isotopes of an element have a mass of 196 amu and 50.0% of…
D. 196 amu