Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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calculate the average atomic mass for oxygen given the following: isoto…
1. E. 0.997572 2. B. 15.9994791 3. D. 0.000381 4. H. 0.0064767 5. C. 0.0020514 6. G. 0.03692348 7. A. 15.9995
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click here to access the interactive simulation. you will practice bala…
In level 1: 2 In level 2: 1 In level 3: 6
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q.3. fill in the blanks using the following word bank. compound homogen…
b
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complete the text with the analysis that most logically connects the cl…
The researchers attributed much of the success of their project to the efficiency and breadth of the citizen scientists’ work.
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4. many fish and aquatic plants can survive a cold winter because a lay…
B. Water expands and becomes less dense when it freezes.
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a) a block of aluminum occupies a volume of 15.0 ml and mass of 40.5 gr…
$2.7$ g/mL
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select the correct compound. reactants undergo chemical reaction to for…
The coefficient of $O_2$ (which is 10 in the given equation instead of 13) is incorrect.
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adapted from presidential retreat by the national parks service camp da…
The underlined sentence is: a piece of relevant supporting evidence It connects ideas in the text by: providing a specific example to support the argument
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to rent a certain meeting room, a college charges a reservation fee of …
$r\leq7$
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answer each question about the following atom when it becomes an ion. p…
Ion: Potassium ion Chemical symbol and charge: $K^{+}$ The ionic charge of + 1 is achieved when the atom loses 1 electron.
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43 multiple choice 1 point when using chemical disinfectants in a healt…
D. Safety Data Sheets (SDS)
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37 multiple choice 1 point if a previously used instrument with visible…
The sterilization process is compromised due to interference by organic material
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32 multiple choice 1 point a facility has begun reprocessing reusable p…
D. Following facility - specific protocols for laundering or chemical disinfection as specified by infection control policies
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28 multiple choice 1 point during an infection control audit, a room is…
B. Use portable HEPA filters and improve air exchange rates
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27 multiple choice 1 point in reviewing safety data sheets (sds) for a …
B. Information on corrosivity and potential for skin or eye irritation
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which of the following gives number of neutrons in an element? clear al…
A. (Atomic mass - Atomic number) of the element
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4 which of the following is not correct for isotopes? they have same at…
They have same number of neutrons
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question 9 (mandatory) (1 point) listen a ¹⁶₈o²⁻ ion has ________ proto…
E. 8; 8; 10
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question 6 (mandatory) (1 point) listen the absorption and emission spe…
C. electrons ### Question 7
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question 3 (mandatory) (1 point) saved isotopes have the same a) atomic…
Question 3: B. number of protons but a different number of neutrons Question 4: Not provided in options (should be de Broglie)
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question 1 (mandatory) (1 point) a $_{17}^{35}$cl atom has _________ pr…
A. 17; 18; 17
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1) what are the three states that water can exist in? 2) what is the sc…
1. Solid, Liquid, Gas 2. Hydrologic Cycle 3. TRUE 4. Precipitation 5. Lemon juice; evaporation and condensation processes similar to water - cycle 6. FALSE 7. TRUE 8. Condensation…
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16 multiple choice 1 point which of the following is the correct defini…
B. An inanimate object that can harbor and transmit infectious agents.
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14 multiple choice 1 point when reprocessing equipment contaminated wit…
A. Utilize autoclaving to ensure spores are effectively destroyed
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and computer models. while the theory of constant proportions has not c…
1. Understanding climate - related processes, discovering new species, and exploring resources. 2. High cost, perception issues, but importance for climate and biodiversity. 3. Us…
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6 multiple choice 1 point what information must be included in a safety…
D. Hazard identification, first aid measures, handling and storage, and exposure controls/personal protection
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1) what are the three states that water can exist in? 2) what is the sc…
1. Solid (ice), liquid (water), gas (water - vapor) 2. Hydrologic cycle 3. True 4. Precipitation 5. Lemon juice; water in lemon juice evaporates similar to evaporation in the wate…
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part ii - isotopes and average atomic mass (unit 2) elements occur as a…
1. $178.6$ u 2. $24.31$ u 3. $6.935$ u 4. $238.0$ u 5. $47.92$ u
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decide whether each sentence is punctuated correctly. use the drop - do…
1. Correct 2. Incorrect; change to "I plan to go skiing with my sisters, and Charles and Boris." 3. Incorrect; change to "Mariana hopes to study chemistry, geometry, and Italian."
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what is an example of irrigation? (1 point) chemicals getting into a wa…
sprinklers being used to water crops
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what is an example of irrigation? (1 point) ships moving goods to ports…
C. sprinklers being used to water crops
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working with enthalpies of reaction and combustion the enthalpy of comb…
$10148$
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calculating enthalpy of reaction compound δh (kj/mol) c6h6 (g) 82.90 co…
$-3169\ kJ/mol$
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determining enthalpy of formation which of these statements are true? c…
The $\Delta H_f$ for $Cl_2(g)$ is 0 kJ/mol, The $\Delta H_f$ for $Br_2(l)$ is 0 kJ/mol, The $\Delta H_f$ for $Hg(l)$ is 0 kJ/mol.
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chemistry atomic structure practice 1 x = element symbol a = mass numbe…
| Name | Symbol | Z | A | #p | #e | #n | Isotopic Symbol | |---|---|---|---|---|---|---|---| | Sodium | Na | 11 | 23 | 11 | 11 | 12 | \(_{11}^{23}Na\) | | Chlorine | Cl | 17 | 35 …
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isotopes and average atomic mass part i: match the word with its defini…
1. $126.9$ amu 2. $55.85$ amu
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calculating enthalpy of reaction ammonia nh₃(g), δhf = - 46.19 kj/mol r…
-175.91 kJ; Exothermic
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recognizing enthalpy of formation which substances have δhf = 0 kj/mol …
$Br_2(l)$, $O_2(g)$, $He(g)$, $Fe(s)$
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check the statements that are a part of the early atomic theory. check …
All of the boxes (Atoms cannot be created or destroyed during a chemical reaction; Atoms combine in whole - number ratios to form compounds; Scientists believe that the atom is ma…
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provide 3 missing symbols and 1 number 208 0 208 a + b_orbital → c 83 -…
1. N. Bi 2. M. e 3. O. Pb 4. P. 82
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provide 3 missing symbols and 2 numbers 16 4 d 1 n + a → b + c e 2 9 0 …
1. E. He 2. A. $\gamma$ (gamma) 3. M. e 4. 88 5. 90
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provide 2 missing symbols and 3 numbers a 110 134 d cm → ru + b + c 96 …
A. 248 B. Sn C. He D. 4 E. \(\gamma\) (gamma)
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provide 2 missing symbols and 2 numbers 188 188 c w → a + b 74 75 d a =…
1. A. $\gamma$, gamma 2. I. 188 3. C. 232 4. K. Re
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provide 4 missing symbols and 2 numbers 232 e 4 0 a → b + c + d 90 88 f…
1. C. 232 2. E. He 3. A. $\gamma$, gamma 4. B. 0 5. F. Th 6. G. 4
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question 10 (0.16666666 points) ar has a larger radius than cl true fal…
Question 10: B. False Question 11: B. False
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question 7 (0.166666667 points) c has more nonmetallic properties than …
Question 7: B. False Question 8: B. False Question 9: A. True
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question 4 (0.166666667 points) cl has a greater ionization potential t…
Question 4: True Question 5: False Question 6: True
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match the element with the description noble gas 1. he alkali metal 2. …
noble gas - 1. He alkali metal - 3. Li halogen - 4. F alkaline earth metal - 2. Be
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match the element to the description heaviest element that can be mined…
1. heaviest element that can be mined on earth: 3. U 2. metalloid: 4. Si 3. transition metal (not inner transition metal): 1. Sc 4. inner transition metal (with lowest atomic numb…
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question 1 (0.666666667 points) match the element to the description no…
nonrepresentative metal: 4. Sc representative metal: 2. Li nonrepresentative nonmetal: 1. none representative nonmetal: 3. H
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compare the number of protons, neutrons, electrons, and nucleons for th…
1. A. 3 2. A. 3 3. A. 3 4. B. 4 5. A. 3 6. A. 3 7. E. 6 8. E. 7 9. F. electrons 10. F. electrons 11. I. neutrons 12. F. electrons
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find the average atomic mass (atomic weight) for lithium on the periodi…
1. C. 6.941 2. A. Li - 7 3. A. Li - 7 4. B. Li - 6
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calculate the average atomic mass for an unidentified element given the…
1. F. 0.78994 2. G. 18.946744 3. E. 0.10001 4. I. 2.498834 5. D. 0.11013 6. H. 2.861463 7. B. 24.307 8. L. Mg
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1 define each term and provide an example of each type of compound. com…
| Compound Type | Definition | Example | |--|--|--| | Molecular | A compound formed by sharing of electrons between non - metal atoms | Water ($H_2O$) | | Ionic | A compound forme…
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o-17 0.0381 16.9991317 amu ( _3_ )(16.9991317 amu) = _4_ amu o-18 0.205…
E. 0.997572, B. 15.9994791, D. 0.000381, H. 0.0064767, C. 0.0020514, G. 0.03692348, A. 15.9995
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calculate the mass in grams of 1 mole of neutrons given the following c…
1. G 2. I 3. Calculate $(1.674927\times 10^{-24}\text{ g})\times(6.02214\times 10^{23})\approx1.00867$ g/mol 4. B
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fill in the information for the anion $^{130}_{x}te^{- 2} x$ is the ato…
1. A. 52 2. A. 52 3. D. 78 4. B. 54 5. E. 130
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fill in the information for the anion $^{128}_{x}te^{- 2}$ x is the ato…
1. A. 52 2. A. 52 3. F. 76 4. B. 54 5. G. 128
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fill in the information for the cation $^{59}_{x}ni^{+3} x$ is the atom…
1. B. 28 2. B. 28 3. E. 31 4. D. 25 5. A. 59
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fill in the information for the isotope ni - 60, or $^{60}_{x}ni$. x is…
1. B. 28 2. B. 28 3. C. 32 4. B. 28 5. F. 60
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answer the questions about the following isotope $^{238}u^{+2}$. the at…
1. K. 92 2. J. 238 3. M. 146 4. L. 90 5. C. 2 6. P. cation
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answer the questions about the following isotope $^{238}u^{+2}$ the ato…
1. K. 92 2. J. 238 3. M. 146 4. L. 90 5. C. 2 6. P. cation
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answer the questions about the following isotope u - 235 or ²³⁵u. the a…
1. K. 92 2. J. 235 3. M. 143 4. K. 92 5. A. 0 6. N. element
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answer the questions about the following isotope $^{1}h^{-1}$ the atomi…
1. B. 1 2. B. 1 3. A. 0 4. (No correct option in given choices, should be 2 for $H^{-}$) 5. F. -1
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answer the questions about the following isotope $^{2}h^{+1}$ the atomi…
1. B. 1 2. C. 2 3. (Based on correct calculation should be 1, not in options) 4. A. 0 5. B. 1
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answer the questions about the following isotope h-3 or $^{3}h$. the at…
1. B. 1 2. D. 3 3. C. 2 4. B. 1 5. A. 0
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complete the following subtraction using significant figures. 5.55555 x…
The result of the subtraction is $555\ \mu g$. The units in the final answer are $\mu g$. So the correct option is $\mu g$.
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it required 500. cal to heat a sample of gold from 25.0 to 35.0 °c. wha…
$(1\ g^{\circ}C/0.0305\ cal)(500\ cal)$ is the correct way to cancel out calories to find the mass of the gold sample. So the correct option is the one with $(1\ g^{\circ}C/0.0305…
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it required 500. cal to heat a sample of gold from 25.0 to 35.0 °c. wha…
1. $\frac{0.0305\ cal}{1\ g^{\circ}C}$ 2. $\frac{1\ g^{\circ}C}{0.0305\ cal}$
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how would you round off your final answer using significant figures? is…
69.7243 amu
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there are two stable isotopes of gallium, $^{69}$ga and $^{71}$ga. calc…
69.724328 amu
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there are two stable isotopes of gallium, ^69ga and ^71ga. calculate th…
isotope abundance relative mass mass contribution Ga - 69 0.601089 68.925580 amu 41.430408 amu Ga - 71 0.398929 70.924701 amu 28.293920 amu
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question 3 (1.666666667 points) there are two stable isotopes of galliu…
41.430408 amu
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there are two stable isotopes of gallium, $^{69}$ga and $^{71}$ga. calc…
A. 0.601089, C. 60.1089/100, D. 0.601089/1
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there are two stable isotopes of gallium, $^{69}ga$ and $^{71}ga$. calc…
abundance
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5.55555 x 10^5 μg + 5.55 x 10^5 μg red gives the greatest uncertainty 1…
True
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question 1 (1.42857143 points) complete the following addition using si…
$\mu g$
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a brainwave pattern is caused by the chemical signals sent between the …
F
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the diameter of a water molecule is 0.00000000033 m. which is the best …
B. 3×10⁻¹⁰ m
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read the passage from chapter 5 of animal farm. at the meetings snowbal…
D. Both Snowball and Napoleon are persuasive leaders and clever animals.
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question 9 (0.75 points) to find the simplest ratio of moles between n …
0.286
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question 9 (0.75 points) to find the simplest ratio of moles between n …
The smallest value among 0.286, 0.543 and 0.316 is 0.286. So you should divide by 0.286. So the answer is 0.286.
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question 2 (0.5 points) saved reflecting back on last week, why do chem…
Atoms are very small, and using their actual counts (like $6.022\times 10^{23}$) would be inconvenient because there are so many of them in even small sample sizes.
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a cylindrical glass tube 15.0 cm in length is filled with ethanol. the …
$1.02\ cm$
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1.5 g/cm^3 x (48 in x 60 in x 6.0 in) x (1 kg / 1000g) x (16.387 cm^3 /…
$1.02\ cm$
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multiple - choice question what should you do if chemicals splash onto …
Jump into the safety shower and stand under it for 15 minutes
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multiple - choice question why do synthetic fabrics pose a safety hazar…
Fuzzy fabrics can catch fire easily and melt
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multiple - choice question which items must always be worn when working…
Gloves, Fitted clothing, A lab apron, Goggles
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7. fill in the blanks. mass # (p⁺ + n⁰)→ ₈¹⁶o ₁₅³¹p ₃₀⁶⁵zn atomic # (p⁺…
| Isotope Name | Isotope Symbol | Protons | Neutrons | Electrons | Atomic Number | Mass Number | |---|---|---|---|---|---|---| | Argon - 40 | $_{18}^{40}Ar$ | 18 | 22 | 18 | 18 | …
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6. fill in the blanks with either positive or negative. a. fluorine ato…
| Isotope Name | Isotope Symbol | Protons | Neutrons | Electrons | Atomic Number | Mass Number | |----|----|----|----|----|----|----| | Oxygen - 16 | $^{16}_8O$ | 8 | 8 | 8 | 8 | …
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social media interactions can cause your brain to release a chemical ca…
B. dopamine
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multiple - choice question glassware and chemical substances can be hea…
A. Directly over a Bunsen burner flame B. In a water bath C. Using a ring stand support
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multiple - choice question why is it dangerous to heat a closed contain…
The pressure created inside the container can burst it
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multiple - choice question when should you shut the gas off to the buns…
A. If the flame goes out C. If you smell gas D. When the flame sputters
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which of the following is the correct bohr model for a neutral berylliu…
(No options are provided in the text to choose from, but a correct Bohr model for beryllium would have a nucleus with 4 protons and 4 neutrons (not shown in basic Bohr models for …
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what makes water different from other liquids like acetone or mineral o…
Water molecules are polar and form hydrogen bonds
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which station showed that water molecules are attracted to each other a…
B. Station 4: Static Electricity and Water
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a bohr model of a magnesium atom is shown below. label the shells on th…
The innermost shell: K - shell The second shell: L - shell The outermost shell: M - shell
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complete the statements. electrons in the outermost shell of an atom ar…
Electrons in the outermost shell of an atom are called valence electrons. All other electrons in the atom are called core electrons.
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multiple - choice question what part of the burner controls the flame h…
The gas valve - located at the bottom of the Bunsen burner