Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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what is an example of a cost - saving strategy for eating healthy? a. b…
a. Buying frozen fruits and vegetables ### Second Question: What function does protein serve in the body?
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multiple-choice question by looking at the bohr models for the elements…
6 (assuming the Bohr models show elements with 6 valence electrons, which corresponds to group 6 in the periodic table)
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the first real model of the atom was proposed in 1803. it described the…
The correct option is: Experiments on the atom provided new evidence that changed the model. (The option with the text "Experiments on the atom provided new evidence that changed …
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homework- protons, neutrons, elements pra... / king foster - subatomic …
To solve for the missing values (Protons, Neutrons, Electrons) in the table, we use the following relationships: - **Protons = Atomic Number** (by definition of atomic number). - …
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complete the rhyme scheme. all nature seems at work. slugs leave their …
Line 1: A Line 2: B Line 3: A Line 4: B Line 5: C Line 6: C
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match the terms to their definition. 1. micronutrients 2. minerals 3. n…
1. micronutrients - nutrients that are needed by the human body, but only in small amounts 2. minerals - inorganic substances that are needed in minimal amounts to regulate, grow,…
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errors in measurement (see table t): percent error is a way for scienti…
The percent error is approximately \(-8.46\%\) (or \(-8.4\%\) if rounded to one decimal place, or as calculated more precisely \(-8.4133\%\) from the handwritten note).
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value: 5 factors that affect the rate of reaction include ______, _____…
a. an increased concentration of reactants, b. An increase in temperature, c. an increase in light, d. an increase in pressure
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complete the rhyme scheme. the sun was shining on the sea, shining with…
The rhyme scheme is A, B, C, B, D, B.
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value: 3 the rate of chemical reaction is the ___ at which reactants ar…
b. speed
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value: 3 an increase in temperature _____ the rate of a reaction. a. de…
b. increases
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value: 3 the rusting of iron is an example of ___ chemical reaction. a.…
a. slow
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question 2 (1 point) what is 56 + (32.00)/(1.2465 + 3.45) written with …
# Explanation: ## Step1: Calculate the denominator First, we calculate the sum in the denominator: \(1.2465 + 3.45\). When adding, we consider the number of decimal places. \(1.24…
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value: 3 the more likely two molecules are to collide every second, the…
a. faster
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value: 4 in endothermic reactions, heat ______ as a reactant in the che…
b. is absorbed
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value: 8 match the description to the terms. a. refers to reactions tha…
a. 3. Endothermic b. 1. Enthalpy c. 2. Exothermic
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value: 4 ____ is signified by the letter h. a. enthalpy b. exothermic c…
a. Enthalpy
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dynamic chemical equilibrium occurs when the rate of a chemical reactio…
b. the same
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le chatelier’s principle can be used to predict the behavior of a syste…
a. Pressure, b. Temperature, c. Concentration
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15. for each substance listed in the table below identify if the molecu…
To solve this, we recall: An **element** is a pure substance made of only one type of atom. A **compound** is a pure substance made of two or more different types of atoms (elemen…
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value: 3 when the concentration of a reactant is ___, the chemical equi…
b. increased
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investigation #1: what happens when you add a mentos to a bottle of die…
Type: descriptive Limitation: variables not controlled (or interferes with environment) ### Investigation #2:
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the letter __ is a symbol for the equilibrium constant. a. k b. l c. p …
a. K
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investigation #1: what happens when you add a mentos to a bottle of die…
Type: descriptive Limitation: variables not controlled ### Investigation #2
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value: 4 ____ reactions are also known as replacement reactions. a. oxi…
d. Displacement
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practice it! sally is a chemist who read an article about how 40% of th…
comparative
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for each row in the table below, decide whether the pair of elements wi…
To solve this, we analyze each row based on element types (metals, non - metals, noble gases) and bonding rules: ### Row 1: Element #1 = Potassium (K, metal), Element #2 = Barium …
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value: 3 identify the strong acid. a. hydrochloric acid b. milk of magn…
a. Hydrochloric acid
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name of element | element symbol | mass number | atomic number | proton…
To solve for the missing values in the table, we use the following relationships in atomic structure: - **Atomic Number (Z)** = Number of Protons = Number of Electrons (in a neutr…
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value: 4 _____, or combination reactions, are the opposite of decomposi…
b. Synthesis
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value: 3 a ___ reaction occurs when the reactant(s) combine with oxygen…
c. combustion
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value: 3 identify the example of a decomposition reaction ○ a. sodium (…
c. 2 hydrogen peroxide molecules (H₂O₂) are broken down into 2 water (H₂O) and 1 oxygen molecule.
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select the text from the paragraph that best helps you understand that …
Proponents of DDT usage pointed to the pesticide as a cost - effective means of controlling mosquito populations in parts of the world with high malaria rates.
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however, pushed back against carsons claims. proponents of ddt usage po…
people who argue for the value of something
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h h number atoms 2 elements 1 compounds 2 if the classification is
The error is in the "Compounds" row; the correct number of compounds is \(0\) (since \(H_2\) is an element, not a compound).
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match each experiment to the subatomic particle it helped discover. sub…
Electron - Cathode ray tube experiment Proton - Gold foil experiment Neutron - Beryllium sheet experiment
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14. diagram: nitrogen (n) atom at center, four hydrogen (h) atoms aroun…
| | Number | |----------|--------| | Atoms | 5 | | Elements | 2 | | Compounds| 1 | (For the "Elements" row, the answer is 2; for "Compounds" row, the answer is 1. If you need indi…
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atoms elements compounds number compounds per ble below vol
The total number of atoms in the given molecule (as per the diagram) is \( \boldsymbol{5} \) (1 nitrogen atom and 4 hydrogen atoms).
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number, atoms, elements, compounds (with handwritten numbers 4, 2, 1) a…
To determine the components and atoms in the compound (let's assume the compound is \( K_2CO_3 \) from the diagram with \( K \), \( C \), \( O \) atoms): ### Step 1: Identify Elem…
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13. diagram of na and cl (two circles, one labeled na, one cl) table wi…
| | Number | |----------|--------| | Atoms | 2 | | Elements | 2 | | Compounds| 1 |
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which of the following is an example of peer norms? a. everyone is usin…
b. Most teens choose to stay drug - free ### Second Question (Marijuana Psychoactive Chemical)
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value: 6 match the description with the chemical reaction type. a. this…
a. 1. Acid - base b. 3. Synthesis c. 4. Decomposition d. 2. Precipitation
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complete the rhyme scheme. across the sky a lowly sigh from west to eas…
For the second line ( "From west to east the sweet wind carried" ), the rhyme scheme letter is $\boldsymbol{b}$ (and following the pattern, the subsequent lines have rhyme schemes…
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value: 3 a ____ is said to have occurred when bonds between atoms are f…
a. chemical reaction
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which of the following rules is true about balancing chemical equations…
a. You can change the coefficient(s) of the chemicals involved. b. You cannot change the subscript(s) of the chemicals involved.
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value: 4 identify the products in the chemical reaction of vinegar and …
a. \( \text{NaC}_2\text{H}_3\text{O}_2 \), c. \( \text{H}_2\text{O} \), e. \( \text{CO}_2 \)
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value: 4 which of the following part of the chemical formula represents…
c. Symbol
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value: 4 which of the following represents the number of the molecules,…
a. Coefficient
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value: 4 which of the following formulas has one carbon atom and four h…
d. $\ce{CH4}$ (Methane)
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value: 4 which of the following parts in the chemical formula represent…
b. Reactant
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value: 3 bases or alkaline are known to ______ protons. a. accept b. do…
a. accept
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value: 4 match the acidity and alkalinity to the ph level. a. sour tast…
1. Acid property: a. Sour tasting 2. Alkaline property: b. Bitter
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value: 3 acids are known to ______ protons. a. accept b. donate # 3/5 <…
b. donate
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solutions with a ___ concentration of hydrogen ions have a low ph. a. h…
a. high
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value: 4 match the acidity and alkalinity to the ph level. a. a solutio…
1. Neutral: c. A solution with a pH of 7. 2. Acidic: b. A solution with a pH below 7. 3. Alkaline/Base: a. A solution with a pH above 7.
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value: 3 electronegativity refers to how well an element ______ electro…
a. attracts, d. hold onto
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value: 5 match the type of bond with the correct difference in electron…
1. Non - polar - covalent bond: a. Electronegativity difference is between 0 - 0.4 2. Polar - covalent bond: c. Electronegativity difference is between 0.5 - 1.7 3. Ionic bond: b.…
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value: 3 the trend for electronegativity on the periodic table is that …
c. left to right, d. bottom to top
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which of the following elements has no electronegativity, and is inert …
a. Neon, b. Argon, c. Helium
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value: 3 the ___ rule refers to the tendency of most atoms to prefer to…
octet
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one of the main properties of covalent bonds is that they form ____ bon…
b. strong
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____ covalent bonds occur when atoms share a pair of electrons in a cov…
b. Nonpolar
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value: 3 when two atoms, with incomplete valence shells, share electron…
a. covalent
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value: 5 match the number of electrons shared in covalent bonds to the …
1. Single covalent bond: b. Two shared electrons 2. Double covalent bond: c. Four shared electrons 3. Triple covalent bond: a. Six shared electrons
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value: 3 in the case of ___ covalent bonds, the electron pair in a bond…
a. polar
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in a solution the _____ is dissolved. options: solute (yellow button), …
A. solute
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6. please identify each element associated with the orbital notation or…
Beryllium (Be) ### Part (b)
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value: 3 an ion is an atom where the number of electrons is _____ to th…
b. not equal
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rank the glasses from most concentrated to least concentrated. options:…
Glass D, Glass B, Glass A, Glass C
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value: 3 a negatively charged ion is called a ____. ○ a. anion ○ b. cat…
a. anion
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the salt is the ......... options: solute, solution, solvant (note: sol…
A. Solute
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value: 3 the complete transfer of valence electrons between atoms is re…
a. Ionic
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cl⁻: which neutral atom is isoelectronic with cl⁻? how many valence ele…
- The neutral atom isoelectronic with $Cl^-$ is Ar. - A neutral Cl atom has 7 valence electrons.
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value: 3 a positively charged ion is called a ______. a. anion b. catio…
b. cation
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what is agitation? color stirring heating size
B. Stirring
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which neutral atom is isoelectronic with n⁻³? ______________ how many v…
The neutral atom isoelectronic with \(N^{3-}\) is Ne (neon). Neutral \(N\) has 5 valence electrons.
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in a solution the _____ is dissolved. options: solvent (yellow button),…
solute (corresponding to the purple option labeled "solute")
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in an aqueous solution the ________ is water. options: solution, solven…
B. Solvent
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what is the rate of dissolution? options: how cold a substance is, how …
C. how quickly a substance dissolves (assuming the orange option is labeled C; if labels differ, adjust to the option with "how quickly a substance dissolves")
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look at the solution of tea and water. what do you think the terms dilu…
B. Diluted means more water, concentrated means less water
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value: 5 identify the positive ion(s) from the list below. mark all cor…
a. Mercury, b. Aluminum
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look at the text below. if there is an error with subject-verb agreemen…
The number of protons in an atom is expressed by that element's atomic number on the periodic table.
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which of the following medication categories require special handling p…
B. Chemotherapy agents
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which statement best describes how a catalyst can speed up a chemical r…
The catalyst decreases the activation energy needed.
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6 c carbon 12.011 according to the image, the atomic mass of carbon is …
B) By adding the number of protons and the number of neutrons
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4. write the electron configuration, for mn and mn⁴⁺. how many electron…
s: - Mn electron configuration: $[Ar] 4s^2 3d^5$ (or $1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^5$) - $Mn^{4+}$ electron configuration: $[Ar] 3d^3$ (or $1s^2 2s^2 2p^6 3s^2 3p^6 3d^3$) - N…
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if the activation energy required for a chemical reaction were reduced,…
A. The rate would increase.
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multiple choice 1 point according to the ph range which substance is mo…
hydrochloric acid
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drag and drop the words or phrases that accurately complete the scenari…
To solve this, we analyze each investigation: ### Investigation #1 - **Type**: Descriptive (since it's observing what happens, no comparison or variable manipulation). - **Limitat…
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it takes 242. kj/mol to break a chlorine-chlorine single bond. calculat…
\(495\)
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8. which example represents a physical change? a. water evaporating b. …
A. Water evaporating ### Question 9
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practice it! sally is a chemist who read an article about how 40% of th…
comparative
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homework 1.4 due in bin directions: read each question carefully and an…
b. Physical change ### Question 2
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the amount of energy that must be absorbed or lost to raise or lower th…
F. is 1 calorie
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which would not increase the rate of dissolution? ice agitation heat sm…
A. Ice
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atoms, ions and molecules naming binary ionic compounds fill in the nam…
The table follows the pattern of binary ionic compound formation: cation ($K^+$) + anion (halide, -1 charge) → empirical formula (1:1 ratio) and name "potassium [halide -ide]". Fo…
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unsaturated solution, saturated solution, supersaturated solution (disp…
B. Solute
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which of the following actions increases the concentration of an aqueou…
B. increasing the amount of the solute (tea)
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3. write the electron configuration, for sr and sr⁺². how many electron…
Sr: $\boldsymbol{1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 5s^2}$ (or $\boldsymbol{[Kr] 5s^2}$) $Sr^{2+}$: $\boldsymbol{1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6}$ (or $\boldsym…
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instructions review the following diagrams below carefully. you will be…
To solve this, we analyze each diagram based on the definitions: - **Element**: Only one type of atom (single or bonded, but same atom). - **Compound**: Molecules with two or more…