Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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which ions, if any, are spectator ions in the reaction agno₃ (aq) + nac…
$Na^{+},NO_3^{-}$
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the total number of lone pairs in ncl3 is ______. 6 8 9 10 13 question …
10
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if the only force of interaction is the dispersion force, you would exp…
1. b. low boiling 2. c. London forces 3. c. chloroform ($CHCl_3$)
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question 6 carbon in cocl2 is a.sp2 hybridized b.sp3 hybridized c.sp hy…
Question 6: A. sp2 hybridized Question 7: None of the provided options are correct. The correct reason is that ion - dipole interactions involve a full - charge (ion) and a partia…
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what type of hybridization can lead to a pyramidal (distorted tetrahedr…
Question 3: b. sp3 Question 4: b. one
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what are the geometry and hybridization around each carbon atom in benz…
Question 1: A. sp2, trigonal planar Question 2: C. $NH_3$
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question 1 (1 point) what does recognition from others indicate about a…
Question 1: Other websites have linked to or cited the source Question 2: The font type of size. Question 3: Check pages labeled About Us, About This Site, Mission, Site Index, an…
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question 5 of 8 prescription opioids share chemical similarities with h…
True
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3) look at the circles for each element, what happens as you move down …
# Explicación: ## Paso 1: Identificar números atómicos y masas atómicas Los números atómicos se representan por el subíndice y las masas atómicas por el superíndice en la notación…
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a chemist prepares a solution of iron(iii) bromide (febr₃) by measuring…
$3.7\times 10^{2}\ \frac{\mu mol}{L}$
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compound important species present when dissolved in water type of comp…
| compound | ionic | molecular | strong acid | weak acid | strong base | weak base | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | $HC_2H_3O_2$ | | $\checkmark$ | | $\check…
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compound important species present when dissolved in water type of comp…
| compound | important species present when dissolved in water | ionic | molecular | strong acid | weak acid | strong base | weak base | | ---- | ---- | ---- | ---- | ---- | ---- …
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predict the products of the reaction below. that is, complete the right…
$2HClO_4+Ca(OH)_2 ightarrow Ca(ClO_4)_2 + 2H_2O$
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classify each chemical compound listed in the table below. |compound|ty…
| compound | ionic | molecular | acid | base | |--|--|--|--|--| | Mg(ClO₄)₂ | √ | | | | | KOH | √ | | | √ | | H₃PO₃ | | √ | √ | | | HCl | | √ | √ | |
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a chemistry student weighs out 0.193 g of citric acid ($h_3c_6h_5o_7$),…
$17.7\ mL$
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6. the atom is electrically neutral because: a) protons = neutrons b) p…
6. b) Protons = Electrons 7. a) J.J. Thomson 8. b) Neutron 9. b) Rutherford
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4. which subatomic particle determines the identity of an element? a) n…
4. b) Proton 5. a) Protons + Neutrons
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name of the student: kamila cruz rodriguez date: 10/3/2025 1. who is kn…
1. b) John Dalton 2. c) Protons and Neutrons 3. b) -1
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question 11. a scientist is analyzing an element in the laboratory. the…
Mass Number = Number of Protons+Number of Neutrons Number of Neutrons = Mass Number - Number of Protons
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a chemist must prepare 525 ml of 1.00 m aqueous barium - chloride (bacl…
404 mL
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question 10. how many protons, electrons, and neutrons are in each atom…
| Atom | Number of Protons | Number of Electrons | Number of Neutrons | | ---- | ---- | ---- | ---- | | $_{32}^{73}\text{Ge}$ | 32 | 32 | 41 | | Osmium - 190 | 76 | 76 | 114 | | $…
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a chemist adds 1.25 l of a 0.16 mol/l potassium dichromate (k₂cr₂o₇) so…
$59\ g$
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pregunta 15 1 pts which of the following are ways that chemical element…
- Single atoms - Lattices - Clusters - Molecules
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pregunta 13 1 pts which of the following best explains why hydrogen can…
Pregunta 13: Hydrogen requires less potential energy to bond and Helium requires more. Pregunta 14: When the attraction between the nuclei and electrons is balanced with the repul…
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a chemist prepares a solution of nickel(ii) chloride (nicl₂) by measuri…
0.34 mol/L
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question 9. complete the table for the following elements. | element | …
| Element | Number of Protons | Number of Electrons | Number of Neutrons | Atomic Number | Mass Number | | --- | --- | --- | --- | --- | --- | | Manganese | 25 | 25 | 30 | 25 | 55…
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atoms that share electrons: have more valence electrons to attract. hav…
- Primera pregunta: have a more equal attraction to the electrons. - Segunda pregunta: low potential energy.
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calculate the volume in liters of a 0.237m potassium dichromate solutio…
$1.48$
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which of the following characteristics best determines whether atoms sh…
The amount of attraction between the positive charge of the nuclei and the electrons.
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a chemist adds 0.25 l of a 5.30m sodium nitrate (nano₃) solution to a r…
$1.3$
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b. converting number of particles to moles n = n / nₐ (nₐ ≈ 6.02×10²³) …
1. $9.7\text{ mol}$ 2. $0.141\text{ mol}$ 3. $12.8\text{ mol}$
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question 8. match the labels to the correct part of the atomic symbols …
From left to right for nuclear notation: Atomic number, Element symbol, Mass number. For hyphen notation: Element name, Mass number.
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pregunta 8 1 pts bonds are more likely to be broken and formed: in bigg…
# Breve explicación: La energía térmica ayuda a romper y formar enlaces químicos. A temperaturas más altas, las moléculas tienen más energía cinética, lo que las hace más propensa…
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a chemist prepares a solution of sodium hyposulfate (na₂s₂o₃) by measur…
$684\ \mu\text{mol/L}$
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pregunta 7 1 pts why are the number of valence electrons more important…
- Valence electrons determine the reactivity of an atom. - Valence electrons are the number of electrons that an element has available for bonding.
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question 7. complete the table showing the number of protons and electr…
| Element Name | Element Symbol | Atomic Number | Number of Protons | Number of Electrons | | ---- | ---- | ---- | ---- | ---- | | Hydrogen | H | 1 | 1 | 1 | | Helium | He | 2 | 2…
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question 6. why is an atom electrically neutral? what does the atomic n…
An atom is electrically neutral because the number of protons equals the number of electrons. The atomic number of an atom represents the number of protons in the nucleus of the a…
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pregunta 6 the periodic table can be used to predict the number of vale…
# Breve explicación: Los elementos en el mismo grupo de la tabla periódica tienen el mismo número de electrones de valencia. El período se asocia con el número de niveles de energ…
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question 5. how many neutrons does a beryllium atom with four protons a…
5
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which of the following describes valence electrons? the electrons in an…
# Breve explicación: Los electrones de valencia son los electrones ubicados en el nivel de energía más externo o "capa" de un átomo. Estos electrones son los que participan en las…
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question 4. what is the mass number of a helium atom that has two proto…
4
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dante owned land that was found to be rich in aluminum. he investigated…
The aluminum is bonded to other elements in the rock.
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question 3. the total number of protons and neutrons in an atom is its
Mass - number
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question 2. the element nitrogen (n) has an atomic number of 7. how man…
Number of Protons = 7 Number of Electrons = 7
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gaseous butane (ch₃(ch₂)₂ch₃) reacts with gaseous oxygen gas (o₂) to pr…
$61.0\%$
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question 1. elements are different because their atoms contain differen…
protons.
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pregunta 1 1 pts atoms of elements in nature exist mostly by themselves…
- Pregunta 1: mostly in combination with other atoms in a molecule or compound - Pregunta 2: Because electrons are electrically attracted to the nucleus
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which of the following is the correct lewis dot structure for a barium …
[Ba]^{2 + } (la segunda opción en la imagen proporcionada)
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gaseous butane (ch₃(ch₂)₂ch₃) reacts with gaseous oxygen gas (o₂) to pr…
66.7 g
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part 2: finding elements for symbols element symbol ge k v no in p as a…
Germanium Potassium Vanadium Nobelium Indium Phosphorus Arsenic Astatine Zirconium Lawrencium
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which of the following is the correct lewis dot structure for an alumin…
# Explicación breve: El aluminio (Al) es un metal del grupo 13. Tiene 3 electrones de valencia. Para cumplir con la regla del octeto, pierde sus 3 electrones de valencia y se conv…
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4. how many particles are in 1.20 mol of sodium sulfide? n = ? n = 1.20…
5. $7.525\times 10^{23}$ particles 6. $1.07156\times 10^{22}$ atoms 7. $1.2642\times 10^{23}$ formula - units 8. $3.34712\times 10^{25}$ molecules 9. $1.505\times 10^{24}$ molecul…
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which of the following is the correct lewis dot structure for a neutral…
# Explicación: ## Paso 1: Encontrar el número de electrones de valencia El cloro tiene 7 electrones de valencia. ## Paso 2: Representar en estructura de Lewis Se representan los e…
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suppose 1.5 g of compound a are consumed in a reaction with 4.0 g of co…
5.5 g 55%
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element symbol xenon barium platinum fluorine argon tungsten magnesium …
xenon: Xe barium: Ba platinum: Pt fluorine: F argon: Ar tungsten: W manganese: Mn silver: Ag radium: Ra
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aqueous hydrobromic acid (hbr) will react with solid sodium hydroxide (…
$35\ g$
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use the periodic table in your textbook part 1: finding symbols for ele…
| ELEMENT | SYMBOL | | ---- | ---- | | copper | Cu | | lithium | Li | | silicon | Si | | zinc | Zn | | thorium | Th | | krypton | Kr | | tin | Sn | | bismuth | Bi | | boron | B | …
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acetylene (c₂h₂) gas and oxygen (o₂) gas react to form carbon dioxide (…
$12.6$
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multiple - choice question in a water molecule, atoms of hydrogen and o…
A. False
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green plants use light from the sun to drive photosynthesis. photosynth…
$10.9\text{ g}$
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multiple - choice question oxygen bonds help hold water molecules toget…
False
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not including water, states of matter generally follow the rule(s) belo…
Solid matter is more dense than liquid matter of the same chemical formula. Liquid matter is more dense than gaseous matter of the same chemical formula. Solid matter is more dens…
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the drawing below shows a mixture of molecules: key carbon hydrogen nit…
1. First question: $O_2$ 2. Second question: $CS_2$ 3. Third question: Assume we have counted 4 molecules of $CS_2$ and 10 molecules of $O_2$. From the balanced equation, 1 mole o…
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in a water molecule, atoms of hydrogen and oxygen are positively charge…
False
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down 1. most active nonmetals 2. group ii metals 3. the atomic number i…
1. Halogens 2. Alkaline earth metals 3. Protons 7. Positive 9. Number 11. Groups
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the movie below shows some molecules in a tiny sample of a mixture of g…
$Cl_2 + H_2 ightarrow2HCl$
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solid magnesium reacts with aqueous iron(iii) chloride to form aqueous …
3Mg(s)+2FeCl₃(aq) → 3MgCl₂(aq)+2Fe(s)
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chlorine gas reacts with solid phosphorus to form phosphorus trichlorid…
$2P(s)+3Cl_2(g) ightarrow 2PCl_3(g)$
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use the periodic table in your textbook to fill in the missing informat…
See the above - filled table for element - symbol correspondences.
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subatomic particles worksheet (fill in the missing information) element…
| Element | Atomic # | Atomic mass | \(\#p^{+}\) | \(\#e^{-}\) | \(\#n^{0}\) | | ---- | ---- | ---- | ---- | ---- | ---- | | magnesium | 12 | 24 | 12 | 12 | 12 | | argon | 18 | 40…
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activity of the elements since metals prefer to give away electrons dur…
1. Na 2. F₂ 3. N 4. Rb 5. Ca 6. K 7. O₂ 8. Br₂ 9. Na 10. S 11. O₂ 12. Cl₂ 13. Fr 14. Rb 15. Cr 16. Cl₂ 17. I₂ 18. Ra 19. Sr 20. K 21. Mg 22. S 23. Li 24. Br₂ 25. F₂ 26. Rb 27. Ra …
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student exploration: ionic bonds vocabulary: chemical family, ion, ioni…
1. Nate can give 1 marker to Clara so that each has a full set. 2. Maggie can give 1 marker to Fred and 1 marker to Florence so that each has 8 markers. 3. Sodium: 1; Chlorine: 7 …
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turned dark pink? an indicator was added to the solution which resulted…
- The property that changes when the color change occurs is pH. - Possible sources of error: Inaccurate measurements, impurities in the sample, indicator error.
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29) what is the value of x when the empirical formula is c₅hₓ and the m…
29) E. none of the above 30) A. KO
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22) how many molecules of nitrogen monoxide are in a 22.6 gram sample? …
E. none of the above
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explain how and why the naoh molarity for part a would or would not be …
1. The molarity of NaOH would not be affected because the moles of KHP, which determine the reaction with NaOH, do not change with the volume of water used to dissolve KHP. 2. The…
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15) how many moles of pb are in 4.71 x 10^21 pb atoms? a) 0.00782 b) 6.…
15) A. 0.00782 16) A. 32.0 17) A. Pb 18) A. 0.761 19) B. $2.09\times 10^{25}$ 20) C. 165 21) A. 44.01
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karin compared four different elements. | boron | oxygen | beryllium | …
Oxygen
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true/false. write t if the statement is true and f if the statement is …
1) F 2) T 3) T 4) T 5) T 6) F 7) T 8) F 9) T 10) F 11) F 12) T 13) D. One mole of water contains 1/2 mole of oxygen atoms 14) D. $1.81\times 10^{24}$
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element symbol # of valence electrons valence sum fluorine f 7 1 30 hyd…
6. For non - metals (excluding hydrogen), valence = 8 - number of valence electrons. 7. Hydrogen has 1 valence electron and the first shell can hold 2. It wants to gain 1 electron…
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19. cations have positive charges. anions have negative charges. what f…
19. D. Electrostatic attraction 20. D. There's no way to tell based on the information given
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1) please provide systematic names for the following compounds: a. b. c…
a. 2,5 - dimethylhexane b. (1 - isopropylcyclohexyl)benzene c. (3E) - 3,4 - diethyl - 3 - hexene d. 1,1 - dibromocyclopentene e. 1 - bromo - 2 - methylbenzene
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the relationship between the number of electrons in an atoms outer shel…
1. It refers to sets of eight. 2. Electrostatic attraction
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16 multiple choice 1 point an atom has 15 total electrons. how many val…
16. C. Five 17. B. Ionic
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an atom with 10 electrons must have how many shells? 1 2 8 10
2
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11 multiple choice 1 point in a neutral atom, which of the following mu…
11. Its number of protons is equal to its number of electrons. 12. It relates to protons and neutrons.
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what is the product of the equation shown? 2na + s₂o₃ →? nas₂o₃ nas₄o₃ …
D. $Na_2S_2O_3$
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activity b (continued from previous page) 5. count: review the lewis di…
| Element | Symbol | # of valence electrons | Valence | Sum | | ---- | ---- | ---- | ---- | ---- | | Fluorine | F | 7 | 1 | 30 | | Hydrogen | H | 1 | 1 | | | Oxygen | O | 6 | 2 | …
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whats the easiest way to balance a chemical equation? trial and error u…
1. A. Trial and error 2. C. Three hydrogen atoms
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how do the products of chemical reactions compare to their reactants? t…
1. The products often have completely different properties than the reactants. 2. There is missing oxygen in the product. 3. Balancing.
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sulfuric acid is made of two hydrogen atoms (h), one sulfur atom (s), a…
1. C. $H_2SO_4$ 2. B. Balancing chemical equation 3. C. Lead
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1 multiple choice 1 point which of the following is a chemical reaction…
1. Sodium and chlorine atoms bond to form salt molecules 2. Hydrogen and oxygen molecules
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in general, the first ionization energy increases as you move from left…
Moving from left to right across period 3, electrons populate the same shell (3s and 3p subshells), and the increase in atomic number signifies that the force of attraction will i…
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3. draw a diagram: draw a lewis diagram of the oxygen molecule in the s…
Oxygen molecule: $:O::O:$ Nitrogen: $:N:::N:$ Ammonia: $H - \underset{\overset{\mid}{H}}{N}-H$ (with lone pair on N) Chlorine: $:Cl - Cl:$ Methane: $H - \underset{\overset{\mid}{H…
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activity b: building molecules get the gizmo ready: • click reset. • tu…
A. 6 B. 2 2 (for the number of pairs of shared electrons in a stable molecule of oxygen)
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activity b: building molecules get the gizmo ready: click reset. turn o…
A. 6 B. 2 2. 2
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1. how many grams of o2 are needed to produce 157.4 g of co2 from the c…
114.5 g (rounded to one decimal place)
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activity a: sharing electrons get the gizmo ready: • click reset. • sel…
1. Two hydrogen atoms can share their single electrons to achieve a stable configuration with 2 electrons each. 2. The Lewis diagram for $H_2$ is $H - H$. 4. The Lewis diagram for…
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what is the minimum grams of protein that a non - athletic male who wei…
Question 1: C. 76 grams Question 2: They consume all food groups with plenty of calories in their diet
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an empty beaker has a mass of 60.0 grams. when mercury is added to the …
140.0 g