Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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question when numbering the parent chain for a particular straight - ch…
C. depends on their location on the molecule
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there are water droplets on the outside of a clean beaker. two chemical…
A. endothermic, because energy is absorbed
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which of these elements is not commonly found in organic compounds? sel…
C. iron
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question identify the organic compounds from the following. a. benzene …
A. a and b
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which characteristic belongs to metal elements? easily gains electrons …
easily loses electrons
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question which of the following statements is not true about inorganic …
C. Inorganic compounds are generally more flammable than organic compounds.
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which characteristic belongs to metalloids? dull brittle small range of…
brittle
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which state of matter is associated with most non - metal elements? pla…
D. gases
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question identify the correct statement regarding water solubility of i…
D. both A and B
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8 multiple choice 1 point selena graphed the data she collected in her …
\(y=\frac{1}{3}x\) (the second option)
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10 what term describes elements that have properties between metals and…
D. Metalloids
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9 which group is known for being very unreactive? a noble gases b halog…
A. Noble gases
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in poetry, creating a rhythmic or musical effect. sur le texte, entoure…
The task requires circling and connecting rhyming words in a French poem as demonstrated in the example.
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8 where are the halogens found on the periodic table? a group 1 b group…
C. Group 17
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24. what element produced the average atomic mass using the following d…
D. Silicon
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ions - practice use your periodic table to complete this worksheet stan…
| Standard Atomic Notation | Atomic Number | Mass Number | # protons | # electrons | # neutrons | | ---- | ---- | ---- | ---- | ---- | ---- | | \(_{8}^{16}O^{2 - }\) | 8 | 16 | 8 …
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7 what is unique about mercury compared to other metals at room tempera…
A. It is a liquid
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23. by knowing the number of protons a neutral atom has, you should be …
the number of electrons in the neutral atom and the name of the element
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6 what is a characteristic of metals? a poor conductors of electricity …
C. Malleable
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22. an element has an atomic number of 80. how many protons and electro…
80 protons, 80 electrons
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5 which elements are known as alkaline earth metals? a magnesium and ca…
A. Magnesium and Calcium
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il revient à ma mémoire des souvenirs familiaux je revois ma blouse noi…
The rhythmic and emotional - evoking nature of the text, along with its fragmented structure, indicates it is a poem.
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4 how are elements in group 1, like lithium and sodium, commonly found …
B. In combination with other elements
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bromine is a _. metal metalloid non - metal none of these
C. non - metal
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silicon is a ___. metal metalloid non - metal none of these
B. metalloid
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barium is a _. metal metalloid non - metal none of these
metal
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aluminum is a _. metal metalloid non - metal none of these
A. metal
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copper is a _. metal metalloid non - metal none of these
metal
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which of the following elements is most likely to pair with sulfur in a…
magnesium (Mg)
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which of the following will pair with a group 7 halogen, such as bromin…
potassium (K)
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in a 1:1 ratio, which of these pairings would create an octet for each …
one magnesium and one oxygen
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q 21 what is the correct electron configuration for chlorine? 1s² 2s² 2…
1s² 2s² 2p⁶ 3s² 3p⁵
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which of the following groups will pair with a group 3 element, such as…
group 5
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q. 30. what particles form the nucleus of an atom? neutrons and electro…
protons and neutrons
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which of the following will pair with a group 6 non - metal, such as ox…
magnesium (Mg)
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19. the numbers of protons, neutrons, and electrons in $_{19}^{39}k^{+}…
19 p, 20 n, 18 e
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which of the following elements is most likely to pair with fluorine in…
C. lithium (Li)
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how many valence electrons does this element have?
7
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15. what element has the following electron configuration? 1s² 2s² 2p⁶ …
A. Mn
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q4 14. how many valence electrons are in copper (cu)? q5 ar 4s² 3d⁸ q6 …
1 (and the electron - configuration of copper is [Ar] 4s¹3d¹⁰)
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q. 13 what one of the following statements about atomic structure is fa…
C. The number of protons and neutrons is always the same in the neutral atom.
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bj: common applications use the information below to answer the questio…
complex geometry
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how many formula units are in 1.5 moles of naoh? ?×10^? formula units o…
Coefficient: 9.03, Exponent: 23
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how many formula units are in 5.5 moles of mgo? ? × 10^? formula units …
3.311; 24
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how many molecules are in 0.75 moles of c2h2? ?×10^? molecules of c2h2 …
Coefficient: 4.515 Exponent: 23
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how many moles are in 7.22 x 10^23 formula units of lioh? ? mol lioh re…
$1.2$
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qe 5. what is the average atomic mass of neon, if there are 175 atoms o…
20.3 amu
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how many moles are in 3.61 x 10^24 molecules of ch3oh? ? mol ch3oh reme…
6
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4. rubidium has two common isotopes, ^85rb and ^87rb. if the abundance …
85.56 u
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qe 3. an ion is formed q4 by either adding or subtracting neutrons from…
By either adding or subtracting electrons from the atom.
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how many molecules are in 2.1 moles of hbr? $\frac{6.02\times10^{23}\te…
Coefficient in green box: $1.2642$, Exponent in yellow box: $24$
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2. which of the following statements is (are) true? $_6^{14}c$ and $_7^…
none of these are true
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how many molecules are in 2.1 moles of hbr? \frac{6.02\times10^{23}\tex…
$1.2642$, $24$
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how many moles are in 2.11 x 10^24 molecules of bef2? 1 mol bef2 / 6.02…
$3.5\ mol$
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how many moles are in 2.11 x 1024 molecules of bef2? lets complete the …
$6.02\times 10^{23}$ molecules of $BeF_2$
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how many molecules are in 2.1 moles of hbr? lets complete the conversio…
$6.02\times 10^{23}$
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part b how does the conservation of mass apply to investigation 2? the …
The mass is conserved because oxygen atoms from the air combine with the copper atoms.
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what can a person do to limit exposure to x - rays? wear sunblock avoid…
wear a protective lead vest
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investigation 1: they melt a sample of solid copper into liquid copper …
Investigation 1 is a physical change, but Investigation 2 is a chemical change because a new substance formed.
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20. a student combines 15 g of hydrogen gas with 120 g of oxygen gas in…
135 g
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1. technician a says batteries are both a chemical and an explosion haz…
C. Both Technician A and Technician B
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part b which explanation best supports your answer to part 1? the numbe…
The number of atoms from the reactants are present in the products, just rearranged.
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naoh + hcl → nacl + h₂o 40g 36.5g? 18g part a what is the mass of sodiu…
58.5 g
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18. in the investigation, a white precipitate (caso₄) formed after the …
The atoms from the reactants are still present in the products, just rearranged into new substances.
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17. students mixed baking soda and vinegar in two different setups: tri…
- In Trial 2, gas escaped from the flask, so the scale showed a lower mass. - In Trial 1, the sealed flask kept all the atoms inside, so the mass stayed the same.
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part b which student explanation is best supported by the evidence from…
The atoms in the reactants were rearranged into new substances, but the total number of atoms stayed the same.
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a student claims, the products weighed the same as the reactants becaus…
The claim is not supported, because the scale showed equal mass in every trial, even when gas was produced.
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14. a student created the model below to show the reaction of methane (…
Take away one oxygen molecule from the reactants so the numbers balance on both sides.
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13. which formula has the greatest total number of atoms? c₂h₅oh ch₃coo…
$C_6H_{12}O_6$
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which formula represents a covalent compound? mgs h₂o₂ cao nacl
$H_2O_2$
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which formula is an ionic compound? co₂ no₂ n₂ naf
NaF
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you work at a manufacturing plant. you need to fill 4 rectangular vats …
D. 40
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12. directions drag and drop the correct answer choice to each answer b…
| 2 Elements | 3 Elements | 4 Elements | | ---- | ---- | ---- | | CO₂, HCl | KNO₃, NaOH | NaAlSi₃O₈ |
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explain why the compound you chose has more oxygen atoms. na₂co₃ has th…
A. $Na_2CO_3$ has three oxygen atoms in its formula, which is more than $CO_2$ (2), $H_2O$ (1), or $CH_4$ (0).
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a monomer is... ○ a large molecule comprised of smaller monomers ○ a sm…
B. a smaller part of a larger molecule; subunit
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11. two students are studying a chemical equation that was used in clas…
Na₂CO₃
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match the definition to the correct vocabulary term. a smaller part of …
"a smaller part of a larger molecule, subunit" - monomer "a large molecule comprised of smaller monomers" - polymer
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compound formula glucose c₆h₁₂o₆ acetic acid (vinegar) ch₃cooh ethanol …
Glucose
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drag and drop the correct answer choice to each answer blank. or, touch…
Evidence of a Chemical Change: A yellow solid forms when two clear liquids are mixed, Baking soda and vinegar release bubbles Not Evidence of a Chemical Change: A piece of ice mel…
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explain how this equation supports the law of conservation of mass. the…
The number of atoms of each element is the same on both sides of the equation. The atoms are just rearranged into new compounds, which shows mass is conserved.
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what is the definition of a chemical bond? o a mutual attraction betwee…
a mutual attraction between the nuclei and electrons in two different atoms
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water (h₂o) is composed of the same elements as hydrogen peroxide (h₂o₂…
The atoms are arranged differently in each molecule.
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what is different between an ionic bond and a covalent bond? an ionic b…
An ionic bond is a bond between charged atoms, while a covalent bond is a bond between neutral atoms.
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what is the definition of a covalent bond? ○ a bond between two atoms ○…
a bond between two atoms
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what is a bond between a positive and a negative ion called? ○ covalent…
D. ionic bond
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what type of ions are mentioned as being present in toxic waste? calciu…
Uranium ions
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you are a research chemist. an experiment requires incubation in a 37 °…
E. 51
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7a student says that na₂so₄ has \7 elements\ because the formula has 7 …
The student is incorrect because elements and atoms are different concepts. The number of elements in $Na_2SO_4$ is 3 (sodium, sulfur, oxygen). The number of atoms is 7 (2 sodium …
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6. a student is studying the formula co₂. using the periodic table, whi…
The symbol C represents carbon, and the symbol O represents oxygen.
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21. label the x - axis of this graph “progress of the reaction” and the…
An enzyme lowers the activation energy ($E_A$) of a chemical reaction, making it easier for the reactants to reach the transition - state and proceed with the reaction.
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11 multiple choice 1 point which of the following is true of a balanced…
The number of atoms of each element remains the same.
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5. a student analyzes the formula h₂so₄. which two statements are suppo…
The formula includes three different elements: hydrogen (H), sulfur (S), and oxygen (O) The subscript 2 means there are two hydrogen atoms.
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question 5 (1 point) what element is represented by 1s2 2s2 2p6 3s2 3p6…
c. Ca
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question 11 (1 point) magnesium has three naturally occurring isotopes.…
24.29 g
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4. the chemical reaction is shown: 2na + cl₂ → 2nacl the periodic table…
The symbol for sodium: Na The symbol for chlorine: Cl The compound they form: NaCl
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which statement communicates accurate information about this reaction? …
No new elements are created in this reaction.
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question 9 (1 point) chlorine 36 has an abundance of 24.22% what is the…
Question 10: 11.506 g (closest to the expected mass of boron - 11 considering atomic mass and context) Question 9: 36.59 g (closest to the expected mass of chlorine - 36 consideri…
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how can a metallic compound be distinguished from an ionic compound? (s…
A. When exposed to light, a metallic compound is often lustrous, while an ionic compound is dull. C. When hit with a hammer a metallic compound is malleable, while an ionic compou…
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2. a student places baking soda into a flask and adds vinegar. the mixt…
The bubbling shows that a gas, a new substance, is being formed.
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question 1 (1 point) in the periodic table hydrogen is placed and group…
a. Hydrogen and helium are both metals. - Incorrect. Helium is a noble gas, not a metal. b. Hydrogen has one outer - shell electron and helium has a full valence shell of electron…