Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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ments east atoms ame ferent rons mple, hich is that of all of ighted ₆¹…
To determine the number of neutrons and mass number for each carbon isotope, we use the following concepts: ### For \( \boldsymbol{_6^{12}C} \): ## Step1: Calculate number of neut…
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substance x is known to exist at 1 atm in the solid, liquid, or vapor p…
To solve this problem, we analyze the heating process of Substance X step by step: ### Step 1: Heat Solid X from \( 20^\circ \text{C} \) to Melting Point (\( 30^\circ \text{C} \))…
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a piece of silver whose mass is 10.4 g is immersed in 20.9 g of water. …
\( 33.2 \) ### For energy absorbed by water:
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exit ticket summary - history of the atomic model (b) fill in the blank…
### John Dalton (1808) - **Contribution blanks**: - First true **atomic theory** - Substances combined in strict **numerical ratios** (or "fixed proportions") - Atoms are **solid*…
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question 7 of 15 view policies current attempt in progress a piece of s…
Approximately $\boldsymbol{33.2}$ J (or more precisely 33.24 J) ### Part 2: Energy absorbed by water
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physical and chemical changes - 7.6c what other changes do you see happ…
To answer this, we can list common physical and chemical changes: ### Physical Changes (no new substance, just form/state change): - **Melting ice**: Ice (solid $\ce{H2O}$) become…
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study the following phase diagram of substance x. use this diagram to a…
s: 1. State of the sample at \( 81^\circ\text{C} \) and 1.0 atm: liquid 2. When pressure decreases by 0.5 atm at constant \( 81^\circ\text{C} \): vaporize (liquid to gas) 3. When …
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an electric heater supplies 46.9 joules of energy to 13.5-g sample of c…
\( 20.5 \) (or a more precise value depending on calculation, but approximately \( 20.5^\circ\text{C} \))
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study the following phase diagram of substance x. use this diagram to a…
### Sub - Question 1: Determine the state at \(-234^\circ C\) and \(1.7\) atm #### Step 1: Convert temperature to Kelvin The formula to convert Celsius to Kelvin is \(T(K)=T(^\cir…
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14. what is electronegativity? 15. how does the electronegativity chang…
Electronegativity is the tendency of an atom to attract electrons in a chemical bond. ### Question 15: How does electronegativity change across a period? Why?
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view policies current attempt in progress the heat capacity of silver i…
254 J
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1. draw and label the parts of an atom. 2. draw a water molecule and la…
- **Nucleus**: Contains protons (positive charge) and neutrons (neutral). - **Protons**: Positively charged particles in the nucleus. - **Neutrons**: Neutral particles in the nucl…
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study the following phase diagram of substance x. use this diagram to a…
liquid ### Second Question:
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10. which of the following digits are not considered significant? ○ zer…
B. zeros to the left of non - zero digits
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8. how many significant figures are present in the measurement 0.004820…
5 (corresponding to the option "5")
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a backpacker climbs a hill. energy is consumed, energy is produced. rad…
Consumed: Chemical energy; Produced: Potential energy (and Thermal energy as a by - product, but the main useful energy change for height gain is potential. If considering the ene…
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current attempt in progress in the following process, energy is transfo…
Consumed energy: Chemical (or sometimes written as "Chemical Energy"), Produced energy: Gravitational Potential (or "Gravitational Potential Energy") (Note: Depending on the optio…
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test review: periodicity 3s²3p¹ 4s²3d¹⁰4p⁵ periodic trends: 1. what is …
Periodicity is the repeating pattern of chemical and physical properties of elements in the periodic table with increasing atomic number, due to periodic electron - configuration …
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question 8 (1 point) what is the charge on a particle that has 17 proto…
e) None of the above
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2. what does this model represent? 1. positive nucleus, electrons movin…
4. Plum Pudding/Blueberry Muffin
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question 7 (1 point) how many electrons are in the element potassium wi…
a) 19
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current attempt in progress explain how each of the following observati…
(a) First blank: potential; Second blank: potential; Third blank: potential; Fourth blank: kinetic (b) First blank: increase; Second blank: kinetic; Third blank: thermal
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question 8 (1 point) what is the atomic mass (in amu) for an element wi…
c) 30.97
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question 5 (1 point) which of the following is/are true about isotopes?…
- The atomic number must be the same - The number of neutrons must be different
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which element has 19 protons in its nucleus? a) f b) k c) cannot determ…
b) K
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a chemical change-- a can easily be reversed by physical means. b alter…
B. alters a substance’s chemical structure to create a new substance
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what are the four main indicators of a chemical change? a state-of-matt…
D. Precipitate, energy exchange, color change, gas production
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select all of the sentences that do not use brackets correctly. □ in 19…
- Dr. Janusch began his experiments during the 1920s [See pages 33 and 34.], but the turning point in his work came in 1935. - The feature of the day is the Hubble Telescope movie…
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which of the following is an example of a chemical change? a mixing two…
A. Mixing two substances and seeing bubbles
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physical and chemical changes - 7.6c physical changes affect the— a col…
D. observable properties of an object
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which of the following are physical properties? a flammable, magnetic b…
B. Dull, nonmagnetic
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elements and compounds - 7.6a, 7.6b data table group a\t\t\tgroup b for…
25 (if Group A total atoms is the question) Or if Group B: $2 + 3 + 1 + 1 + 3 = 10$ Since the problem isn't fully stated, but based on the table, a common task is summing atoms. L…
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name wendy ponce, sept,10 period 2 phet -building an atom part 1 and 2 …
Protons and neutrons ### Question 4
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3.3 energy changes in chemical reactions in the following reaction, the…
The energy required to break a mole of \( O_2 \) (i.e., break the \( O=O \) bond in one mole of \( O_2 \) molecules) is \( \boldsymbol{498} \, \text{kJ/mol} \).
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multiple-choice question which of the following are elements? select al…
A. (assuming A is an element), B. (assuming B is an element), C. (carbon, an element), D. (assuming D is an element) (Note: The exact answer depends on what A, B, D represent. If,…
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question 7 how many bonds (pairs of electrons) are in ch₂=ch₂? two bond…
D. Six bonds
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the repetition of similar sounds, typically at the end of lines in poet…
rhyme ### 2. Second Question
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calculate the amount of heat needed to boil 116. g of ethanol (ch₃ch₂oh…
To solve the problem of calculating the heat needed to boil ethanol, we need to consider three steps: heating the ethanol from \(-75.3^\circ \text{C}\) to its boiling point, vapor…
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how does free verse differ from other forms? a. it lacks rules of struc…
a. It lacks rules of structure, meter, and rhyme scheme ### Second Question: What is the main characteristic of free verse poetry?
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question 10 identify the formal charge for c in ch₃⁻. ○ −1 ○ 1 ○ 0 ○ 2
-1
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one method for estimating the enthalpy change for a reaction, δ h, is t…
-348
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the article states, ich in carbon, the solar-orbiting bennu is believed…
Carbon is an element.
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32 thermodynamics a chemical reaction absorbs 200 j of heat and causes …
-150 J
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what is the best definition of strategy? (1 point) ○ a plan for achievi…
A. a plan for achieving something
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11 matching 0.1 points what answer should be reported, with the correct…
# Explanation: ## Step1: Perform Multiplication First, calculate \( 471.23 \times 8.054 \). \( 471.23 \times 8.054 = 471.23\times(8 + 0.05 + 0.004)=471.23\times8+471.23\times0.05 …
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of, relating to, or derived from living matter. contains carbon escribi…
Orgánico
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(01.04 mc) matt has four samples of substances: sample a: 8 ml of hydro…
Sample B and Sample D
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(01.04 lc) what best defines an extensive property of a substance? a ph…
A. A physical property that depends on the sample size
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(01.03 mc) an object has a mass of 4.9 g and a volume of 14 ml. what is…
0.35 g/mL (corresponding to the option: 0.35 g/mL)
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which statement describes the properties of lanthanoids and actinoids? …
C. They are malleable and lustrous, and they tend to conduct both electricity and thermal energy (assuming the third option is labeled C, if the original options were labeled as A…
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in which group of elements does tellurium (te) belong? (1 point) alkali…
metalloids (the option with text "metalloids")
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based on patterns in the periodic table, which element is the least mal…
phosphorus (P)
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how does mercury differ from other metals? (1 point) it is not lustrous…
It is not solid under normal conditions.
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an element is highly conductive, highly reactive, soft, and lustrous. t…
alkali metals
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27. (03.07 hc) \for many americans, these four months have brought sorr…
Orientation—President George W. Bush included the story of a person who lost a loved one during the attacks.
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to the correct number of significant figures? 25.64 - 19.202 a) 6.438 b…
c) 6.44
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question 5 (1 point) which of the following is the correct answer for t…
c) 6.44
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question 3 (1 point) how many significant figures are in the number 301…
e) 6
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analysis and conclusion questions: 1. which water level heated up the f…
The 100 mL water level heated up the fastest. We know this by looking at the graph: the line representing 100 mL has the steepest slope (shows the most rapid increase in temperatu…
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question 8 a mixture of two or more substances that are uniformly mixed…
A. Solution
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what is made up of solutes and solvents? ○ suspension ○ solutions ○ col…
B. Solutions (assuming the options are labeled as A. Suspension, B. Solutions, C. Colloid) ### Second Question (You can make a solution more concentrated by adding what?)
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what is the concentration of a solution? the amount of solvent needed t…
The amount of solute that has been dissolved in a given amount of solvent ### Second Question (Which is an example of a solute?)
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5. if corey produces 7.3 grams of sodium carbonate in a reaction that r…
To solve this problem, we need to know the balanced chemical equation for the reaction involving sodium carbonate and sodium phosphate. Assuming the reaction is between calcium ph…
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what is the substance called that dissolves the other substance in a so…
C. Solvent ### Second Question (In a saltwater solution, what substance is considered the solvent?)
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question 1 what is the substance called that is being dissolved in a so…
D. Solute
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read: concept vocabulary identify the choice that best answers the ques…
C. No one shows up for Joshua's thirteenth birthday party.
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check all the ways listed below that ensure accurate reading of volume …
- using subtraction to determine the volume dispensed - making sure that you read the volume with the liquid inside the pipette at eye level - ensuring that air bubbles are not in…
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3. an object has a mass of 35.0 grams. on maxs balance, it weighs 34.85…
The percent error of Max's balance is approximately \( 0.43\% \) (or more precisely \( 0.4286\% \)).
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2. if the percent yield of a reaction was 65.0% and its theoretical yie…
The actual yield is $0.424\ \text{g}$ (or $0.4238\ \text{g}$ depending on precision)
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the diagram shows the logarithm of the first 13 ionisation energies of …
B. The element is aluminium.
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19. the chemical equation for formation of table salt is shown. 2na + c…
The total number of atoms in the sodium chloride molecules is equal to the total number of atoms in the sodium and chlorine gas molecules.
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1a. shane tested the properties of four samples and recorded data in th…
Sample 1
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the table shows the different physical properties an element can posses…
insulator, brittle
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the table shows the different physical properties an element can posses…
insulator
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16. matter can undergo physical or chemical changes. which of these are…
Freezing a popsicle, Breaking an egg
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16. matter can undergo physical or chemical changes. which of these are…
The examples of physical changes are: - Breaking an egg (checkbox should be selected) - Freezing a popsicle (checkbox is already selected)
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question 2 2.1 define the term molar mass. (2) 2.2 calculate the percen…
Molar mass is the mass of one mole of a substance (in g/mol), numerically equal to its relative atomic/molecular mass (sum of atomic masses of constituent atoms) in amu, scaled to…
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which of these are examples of physical changes? options: burning paper…
Freezing a popsicle
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15. the particle diagram below represents four molecules of a substance…
The particle diagram with four molecules, each consisting of one black and one white particle (same as the original in terms of molecular composition, just possibly different spac…
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a new element has been discovered that is a semiconductor, brittle as a…
In columns 13 - 16, because it is a metalloid
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the result of two liquids forming a solid is called options: a precipit…
a precipitate
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4. what is the density for a powder that weighs 40.0 g and when added t…
\( \approx2.67\space g/mL \) ### Problem 5 (already has a solution, verifying)
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question 1 (1 point) fatty acids are hydrophobic (water fearing) molecu…
True ### Question 2
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which of the following demonstrate evidence of a chemical change? selec…
- Substance sinking: Chemical Change Has Not Occurred - Precipitate forming: Chemical Change Occurred - Change in shape: Chemical Change Has Not Occurred - Production of gas: Chem…
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11. which of the following is examples of a chemical change? options: w…
Rust forming on a car door
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fatty acids are hydrophobic (water fearing) molecules; because they are…
A. True ### Question 2
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a pharmacy technician has just finished preparing a chemotherapy medica…
A. Hazardous medications (H)
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10. calcium nitrate ca(no₃)₂ is often used in fertilizers. which elemen…
Elements: Calcium (Ca), Nitrogen (N), Oxygen (O) (3 elements in total). Number of atoms: - Calcium (Ca): 1 atom - Nitrogen (N): 2 atoms - Oxygen (O): 6 atoms
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question 9. directions: drag and drop the correct answer choice to each…
First blank: color Second blank: was
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9. directions drag and drop the correct answer choice to each answer bl…
The student thinks a chemical change is occurring because when the two solutions mix, the student observes a unexpected change in \boxed{color}. Therefore, the student claims that…
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name: navel seg date: september learner / securing lo: swbat compare th…
- Primera línea (después de "A"): solution - Segunda línea (después de "which"): a solute - Tercera línea (después de "is"): dissolved (En los dibujos: salt (solute) + water (solv…
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8. when baking soda (sodium bicarbonate, nahco₃) reacts with vinegar (a…
60 g
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put the following numbers in order of increasing amount of sig figs (i.…
1. \(9.6\times10^{3}\) 2. \(7.57\times10^{6}\) 3. \(0.6363\) 4. \(737290\) 5. \(7.6136\times10^{5}\) 6. \(0.04321400\)
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students are testing the reactivity of different solutions by mixing th…
- Trials 3 and 4 formed a new substance because both trials resulted in a precipitate. - (Another correct one, if exists, but based on the table and options, the above is one, and…
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7. students are testing the reactivity of different solutions by mixing…
The correct option (from the visible choices) is: *Trials 3 and 4 formed a new substance because both trials resulted in a precipitate* (the yellow-highlighted option). If a secon…
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students are testing the reactivity of different solutions by mixing th…
To solve this, we analyze each option against the data table: ### Analyzing Option 1: "Trial 1 and 4 formed a new substance because both trials resulted in a change in shape." - T…
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an element has the following properties: - very highly reactive - shiny…
A. Location A
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the chemical equation for photosynthesis is: 6co₂ + 6h₂o → c₆h₁₂o₆ + 6o…
The number and type of atoms on both sides are the same, showing that atoms are rearranged, not created or destroyed.
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how many significant figures are in the measurement 1.050 l? a. 1 b. 2 …
d. 4
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20. —- a measuring cup that is accurate but not precise. 21. a student …
To solve the problem of finding the volume of a rock sample with a density of \(0.78 \, \text{g/cm}^3\) and a mass of \(24.8 \, \text{g}\), we use the formula for density: \[ ho =…