A pure sample of the R enantiomer of a compound has a specific rotation, [ α], of +20 °. A solution containing 0.2 g/mL of a mixture of enantiomers rotates plane polarized light by −2 ° in a 1 dm polarimeter. What is the enantiomeric excess (%ee) of the mixture?

Answers

Answer 1

Answer:

Explanation:

The specific rotation of the sample is -2 degrees/0.2 g/mL of mixture

This equals -10 degrees/g/mL of sample.

let the proportion of the R (+) enantiomer be x. The proportion of the S (-) enantiomer in the mixture will be given by (1-x).

specific rotation of the mixture = proportion of R enantiomer* its specific rotation + proportion of S enantiome * its specific rotation

i.e.

-10 = x *(+20) + (1-x)*(-20)

-10 = 20x-20 + 20x

-10+20 = 40x

+10 = 40 x

x=10/40 = 25%

Since the proportion of the other enantiomer is 1-x, it is 0.75 or 75%

So the mixture contains 25% R, 75% S, giving you an excess of 50%.

Answer 2

Answer:

10%

Explanation:

Enantiomeric excess is a way of describing how optically pure a mixture is by calculating the purity of the major enantiomer. It can range from 0%-100%. Enantiomeric excess ( ee ) can also be defined as the absolute difference between the mole fractions of two enantiomers.

Enantiomeric excess is also called optical purity. This is because chiral molecules cause the rotation of plane-polarized light and are said to be optically active. An enantiomerically pure sample has an enantiomeric excess of 100 percent

Enantiomeric excess = observed specific rotation/specific rotation of the pure enantiomer x 100

From the data given in the question;

observed specific rotation= -2°

specific rotation of the pure enantiomer = +20°

Therefore;

ee= 2/20 ×100

ee= 10%


Related Questions

Problem PageQuestion Liquid hexane CH3CH24CH3 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. Suppose 60. g of hexane is mixed with 74.5 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to 3 significant digits.

Answers

Answer:

43.45g of water would be produced from the reaction.

Explanation:

Liquid became reacts with oxygen to produce carbon dioxide and water.

This type of reaction is known as combustion reaction between alkanes.

Equation of reaction.

Assuming the reaction occurs in an unlimited supply of oxygen,

2C₆H₁₄ + 19O₂ → 12CO₂ + 14H₂O

From the above equation of reaction,

2 moles of C₆H₁₄ reacts with 19 moles of O₂ to produce 14 moles of H₂O.

To find the theoretical mass,

Number of moles = mass / molar mass

Molar mass of C₆H₁₄ = 86g/mol

Molar mass of O₂ = 16g/mol × 2 = 32g/mol

Molar mass of H₂O = 18g/mol

Mass of H₂O = number of moles × molar mass

Mass of H₂O = 14 × 18 = 252g

Mass of C₆H₁₄ = number of moles × molar mass

Mass of C₆H₁₄ = 2 × 86 = 172g

Mass of O₂ = number of moles × molar mass

Mass of O₂ = 19 × 32 = 608g

From the equation of reaction,

172g of C₆H₁₄ reacts with 608g of O₂ to produce 252g of H₂O

(172 + 608)g of reactants produce 252g of H₂O

780g of reactants produce 252g of H₂O

(60 + 75.5)g of reactants will produce a x g of H₂O

780g of reactants = 252g of H₂O

134.5g of reactants = x g of H₂O

X = (134.5 × 252) / 780

X = 43.45g of H₂O

Therefore, 43.45g of H₂O would be produced from 60g of hexane and 74.5g of oxygen

Answer:

[tex]m_{H_2O}=30.9gH_2O[/tex]

Explanation:

Hello,

In this case, the combustion of hexane is given by:

[tex]C_6H_{14}+\frac{19}{2} O_2\rightarrow 6CO_2+7H_2O[/tex]

The next step is to compute the reacting moles of hexane:

[tex]n_{C_6H_{14}}=60gC_6H_{14}*\frac{1molC_6H_{14}}{86gC_6H_{14}} =0.698molC_6H_{14}[/tex]

Then, the moles of hexane consumed by 74.5 g of oxygen using the molar ratio in the chemical reaction (1:19/2):

[tex]n_{C_6H_{14}}=74.5gO_2*\frac{1molO_2}{32gO_2} *\frac{1molC_6H_{14}}{19/2molO_2} =0.245molC_6H_{14}[/tex]

Therefore, as less moles of hexane are consumed by oxygen, it is in excess, so we compute the mass of water produced by the consumed 0.245 moles of hexane:

[tex]m_{H_2O}=0.245molC_6H_{14}*\frac{7molH_2O}{1molC_6H_{14}}*\frac{18gH_2O}{1molH_2O} \\\\m_{H_2O}=30.9gH_2O[/tex]

Best regards.

carbon dioxide is a non-polar molecule true or false​

Answers

Answer:

True

Explanation:

Due to the arrangement of the molecule, a carbon dioxide molecule is non-polar.

Smooth muscle myosin is a motor protein that plays a crucial role in the contraction of smooth muscle. If this protein has a molar mass of 480,000 grams/mol, what is the mass, in grams, of 27 moles of smooth muscle myosin

Answers

Answer: Thus the mass, in grams, of 27 moles of smooth muscle myosin is 12960000 grams

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass, occupies 22.4 L at STP  contains avogadro's number [tex](6.023\times 10^{23})[/tex] of particles.

Molecular mass of protein = 480,000 g/mol

Thus 1 mole of protein weighs = 480,000 g

So 27 moles of protein weighs = [tex]\frac{480,000}{1}\times 27=12960000g[/tex]

Thus the mass, in grams, of 27 moles of smooth muscle myosin is 12960000 grams

Which of the following is evidence for a physical change? A) burning B) fizzing C) evaporating D) rusting

Answers

The answer is D) rusting
I’m not sure and if it’s wrong I’m so sorry

Answer:c

Explanation: rusting, burning and fuzzing are all examples of chemical reactions/changes.

5. Rosalind Franklin was a key figure in the discovery of the structure of DNA, yet she
was not included in the Nobel Prize which was awarded to Watson and Crick. Carry out
some research to find out how she contributed to this work and use the space below
to write up your findings​

Answers

Answer:

Explanation:

Search for "Rosalind Franklin: DNA's unsung hero - Cláudio L. Guerra" which basically summarizes what Rosalind did and how we was snubbed from receiving the noble prize even though she had vast and critical evidence to highlight the structure of DNA. You can look for more sources but I can tell you a quick recap:

Rosalind Franklin was born in an era where women scientists or workers were very uncommon and they were even discriminated and looked down upon. After her phD., she was working to find the structure of DNA and soon she was able to form an x-ray image of it. However, her lab colleague took the picture and showed it to other scientists (Watson and Crick) without the knowledge or permission of Rosalind. Here Rosalind was working on analyzing her data and on other part of world Watson and Crick were doing the same. Based on Watson and Crick's analysis, they came up with the correct structure of DNA and soon Rosalind got done as well. Both submitted their paper to journal, however, the journal placed Watson and Crick paper before Rosalind (making it look like Rosalind just confirmed what Watson and Crick proposed). This made it look like Watson and Crick were geniuses behind DNA structure whereas, in reality, it was Rosalind. She would have received Nobel Prize but she died of Cancer and Nobel prizes are not awarded to dead people.

Which of the following bases is the WEAKEST? The base is followed by its Kb value. Group of answer choices HOCH2CH2NH2, 3.2 × 10-5 (CH3CH2)3N, 5.2 × 10-4 NH3, 1.76 × 10-5 C5H5N, 1.7 × 10-9 Since these are all weak bases, they have the same strength.

Answers

Answer:

C₅H₅N being the weakest base

Explanation:

A weak base (B) is defined as a chemical compound that, in reaction with water, produce a small quantity of BH⁺

The general reaction is:

B + H₂O ⇄ BH⁺ + OH⁻ Where Kb is defined as:

Kb = [BH⁺] [OH⁻] / [B]

That means the smallest Kb is the weakest base because is producing the smallest quantity of BH⁺.

In the problem, the smallest Kb is C₅H₅N being the weakest base.

The decay of a radioactive material is monitored using a Geiger counter. At the start, the count rate is 2000 decays/minute. Four hours later the decay rate is 500 counts/min. What is the half-life of the material?

Answers

Answer:

The half-life of the material is 2 years

Explanation:

Given;

initial count rate = 2000 decays/minute

final count rate =  500 counts/min

decay time = Four hours

To determine the half life of the material; we create a simple decay table that matches the decay time and count rates.

time (years)                     count rate

0                                    2000 decays/minute

2                                     1000 decays/minute

4                                     500 decays/minute

Half life is the time intervals = 2 years

Also using a formula;

[tex]N = \frac{N_o}{(t/2)^2} \\\\N_o-is \ the \ initial \ count\ rate\\\\N-is \ the \ final \ count\ rate\\\\t/_2 - is \ the\ half\ life \\\\N = \frac{N_o}{(t/2)^2} \\\\500 = \frac{2000}{(t/2)^2}\\\\(t/_2)^2 = \frac{2000}{500} \\\\(t/_2)^2 = 4\\\\t/_2 = \sqrt{4} \\\\t/_2 = 2 \ years[/tex]

Therefore, the half-life of the material is 2 years

                                                               

Which option describes a similarity and a difference between isotopes of an element? A. same atomic number; different number of protons B. same number of protons; different atomic number C. same atomic number; different mass number D. same mass number; different atomic number E. same number of neutrons; same number of protons

Answers

Answer:

c

Explanation:

g Identify the type of reaction [(combination (c), decomposition (d), combustion (co), single replacement (sr), double replacement (dr) , or neutralization (n)] and write a balanced equation. If there is no reaction, write NR. Aqueous ammonium phosphate reacts with aqueous calcium sulfide.

Answers

Answer: [tex]2(NH_4)_3PO_4(aq)+3CaS(aq)\rightarrow Ca_3(PO_4)_2(aq)+3(NH_4)_2S(s)[/tex] is a double displacement reaction (dr).

Explanation:

A double displacement reaction (dr) is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

[tex]2(NH_4)_3PO_4(aq)+3CaS(aq)\rightarrow Ca_3(PO_4)_2(aq)+3(NH_4)_2S(s)[/tex]

Combination reaction (C) is defined as the reaction where substances combine in their elemental state to form a single compound.

Single displacement reaction (sr) is defined as the reaction where more reactive element displaces a less reactive element from its chemical reaction.

Decomposition reaction (d) is defined as the reaction where a single substance breaks down into two or more simpler substances.

Combustion (Co) is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.

Calculate the pH of a 0.020 M H2CO3 solution. At 25 °C, Ka1 = 4.3 × 10-7. H2CO3(aq) + H2O(l) ↔ H3O+(aq) + HCO3-(aq)

Answers

Answer:

Explanation:

H₂CO₃(aq) + H₂O(l) ↔ H₃O⁺(aq) + HCO₃⁻(aq)

Let d be the degree of dissociation

.02( 1-d )                              .02d          .02d

Dissociation constant Ka₁ is given

4.3 x 10⁻⁷  = .02d x .02d / .02( 1-d )

= .004 d² / .02  ( neglecting d in denominator )

= .02 d²

d² = 215 x 10⁻⁷

d = 4.636 x 10⁻³

= .004636

concentration of H₃O⁺

= d x .02

= .004636 x .02

= 9.272 x 10⁻⁵

pH = - log [ H₃O⁺ ]

= - log ( 9.272 x 10⁻⁵ )

5 - log 9.272

= 5 - .967

= 4.033 .

Use the formation reactions below such that when added together, they match the balanced equation for the combustion of methane.
Cgraphite(s)+ 2H2(g) → CH4(g) ΔH 1=−74.80kJ
Cgraphite(s)+ O2(g) → CO2(g) ΔH2=−393.5k
H2(g)+ 1/2O2(g) → H2O(g) ΔH3=−241.80kJ
Calculate ΔHrxn for the combustion of methane, CH4(g).
CH4(g)+ 2O2(g) → CO2(g)+ 2H2O(g) ΔHrxn =--------------kJ

Answers

Answer:

ΔH of the reaction is -802.3kJ.

Explanation:

Using Hess's law, you can know ΔH of reaction by the sum of ΔH's of half-reactions.

Using the reactions:

(1) Cgraphite(s)+ 2H₂(g) → CH₄(g) ΔH₁ = −74.80kJ

(2) Cgraphite(s)+ O₂(g) → CO₂(g) ΔH₂ = −393.5k J

(3) H₂(g) + 1/2 O₂(g) → H₂O(g) ΔH₃ = −241.80kJ

The sum of (2) - (1) produce:

CH₄(g) + O₂(g) → CO₂(g) + 2H₂(g) ΔH' = -393.5kJ - (-74.80kJ) = -318.7kJ

And the sum of this reaction with 2×(3) produce:

CH₄(g) + 2 O₂(g) → CO₂(g) + 2H₂O(g) And ΔH = -318.7kJ + 2×(-241.80kJ) =

-802.3kJ

Nitrogen forms more oxides than any other element. The percents by mass of in three different nitrogen oxides are (1) (II) and (III) 25.94 For each compound, determine (a) the simplest whole-number ratio of to and (b) the number of grams of oxygen per 1.00 of nitrogen.

Answers

Complete question;

Nitrogen forms more oxides than any other element. The percents by mass of N in three different nitrogen oxides are (|) 46.69%;(II) 36.85 %; (III) 25.94%. For each compound, determine (a) the simplest whole-number ratio of N to O, and (b) the number of grams of oxygen per 1.00 g of nitrogen.

Answer:

a. (i) The ratio is 1:1 , the formula = NO  (ii)The ratio is 1 : 1.5 which is  2 : 3, the formula = N₂O₃  (iii) The ratio is 1 : 2.5 which is 2:5 , the formula = N₂O₅

b. (i)number of grams of oxygen = 53.31/46.69 = 1.14 g

(ii)number of grams of oxygen = 63.15/36.8 = 1.71 g

(iii)number of grams of oxygen = 74.06/25.94 = 2.855 g

Explanation:

a.

(i) The percentage by mass of the nitrogen in Nitrogen oxide (i) is 46.69% which is taken as 46.69 grams . Since the other element is oxygen the mass of oxygen will be 100 - 46.69 = 53.31 grams.

The relative atomic mass of Nitrogen and oxygen is 14 amu and 16 amu respectively.

Therefore, to know the whole number ratio of N and O we find the number of moles.

number of moles of N = 46.69/14 = 3.335

number of moles of O = 53.31/16 = 3.332

The ratio is 1:1 , the formula = NO

(ii)

number of moles of N = 36.85/14 = 2.632

number of moles of O = 63.15/16 = 3.947

The ratio is 1 : 1.5 which is  2 : 3, the formula = N₂O₃

(iii)

number of moles of N = 25.94/14 = 1.85

number of moles of O = 74.06/16 = 4.63

The ratio is 1 : 2.5 which is 2:5 , the formula = N₂O₅

b.

(i) 46.69 g of nitrogen  = 53.31 g of oxygen

1 g of nitrogen = ? of Oxygen

number of grams of oxygen = 53.31/46.69 = 1.14 g

(ii)

Using similar method in b(i)

number of grams of oxygen = 63.15/36.8 = 1.71 g

(iii)

Using similar method in b(i)

number of grams of oxygen = 74.06/25.94 = 2.855 g

If 200.4g of water is mixed with 101.42g of salt the mass of the final solution would be reported as

Answers

Answer:

301.8 g

Explanation:

We prepare a solution with 200.4 g of water (solvent) and 101.42 g of salt (solute). The mass of the solution is equal to the sum of the mass of the solvent and the mass of the solute.

m(solution) = m(solute) + m(solvent)

m(solution) = 200.4 g + 101.42 g

m(solution) = 301.8 g (we round-off to one decimal according to the significant figures rules)

What must happen for an ionic bond to be created between two elements?

Answers

Answer:

they must be heated

Explanation:

What occurs when potassium reacts with bromine to form potassium bromide?

1) Electrons are shared and the bonding is ionic.

2) Electrons are shared and the bonding is covalent.

3) Electrons are transferred and the bonding is ionic

4) Electrons are transferred and the bonding is covalent.

Answers

2) Electrons are shared meaning the bond is covalent.

Fill in the blank: If an atom is in column V (or 15), it will most likely ____________ to fulfill the octet rule.

Gain 3 electrons

Lose 5 electrons

Gain 5 electrons

Lose 5 protons

Gain 3 protons

Answers

Answer:

If an atom is in column V (or 15), it will most likely gain 3 electrons to fulfill the octet rule.

Explanation:

The octet rule defines the property that atoms have to complete their last energy level with eight electrons to achieve stability through an ionic, covalent or metallic bond.

The pair of electrons that are transferred or gained belong to the last shell of the atom. If an atom is in column V (or 15), it means that it has 5 electrons in its last shell. So an atom in this group is more likely to gain 3 electrons to achieve stability than to lose the 5 electrons it has.

If an atom is in column V (or 15), it will most likely gain 3 electrons to fulfill the octet rule.

A.  Gain 3 electrons

What does Octet rule say?

The octet rule defines the property that atoms have to complete their last energy level with eight electrons to achieve stability through an ionic, covalent or metallic bond.

The pair of electrons that are transferred or gained belong to the last shell of the atom. If an atom is in column V (or 15), it means that it has 5 electrons in its last shell. So an atom in this group is more likely to gain 3 electrons to achieve stability than to lose the 5 electrons it has.

Thus, correct option is A.

Find more information about Octet rule here:

brainly.com/question/865531

how many grams of NH3 can be produced from 2.51 mil of N2 and excess H2 ?


please help! due in a bit

Answers

Answer:

85.34g of NH3

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

N2 + 3H2 —> 2NH3

Step 2:

Determination of the number of moles of NH3 produced by the reaction of 2.51 moles of N2. This is illustrated below:

From the balanced equation above,

1 mole of N2 reacted to produce 2 moles of NH3.

Therefore, 2.51 moles of N2 will react to produce = (2.51 x 2)/1 = 5.02 moles of NH3.

Therefore, 5.02 moles of NH3 is produced from the reaction.

Step 3:

Conversion of 5.02 moles of NH3 to grams. This is illustrated below:

Molar mass of NH3 = 14 + (3x1) = 17g/mol

Number of mole of NH3 = 5.02 moles

Mass of NH3 =..?

Mass = mole x molar Mass

Mass of NH3 = 5.02 x 17

Mass of NH3 = 85.34g

Therefore, 85.34g of NH3 is produced.

What is the reactant(s) in the chemical equation below?
2Al(s) + 2NaOH(aq) + 2H2O()
2NaAlO2(aq) + 3H2(9)
A. 2Al(s) + 2NaOH(aq) + 2H200)
B. 2NaAlo2(aq) + 3H2(g)
C. 2Al(s)
D. 3H2(g)

Answers

Answer:

A

Explanation:

They are all found in the reactants side

What is the mass of 3.75 moles of NaCI? ( Na= 22.99g/mol, CI= 35.45 g/mol)

Answers

Answer:

219.15 grams

Explanation:

What is the mass of 3.75 moles of NaCI? ( Na= 22.99g/mol, CI= 35.45 g/mol)

Mole of Na = 22.99g

Mole of Cl = 35.45g

For NaCl we have ratio of 1:1, so we have 1 Na for every Cl

So we just add the two together to get the molar mass of NaCl which is

22.99 + 35.45 = 58.44g/mol

And we know we have 3.75 moles of NaCl so we multiply that by the molar mass of NaCl to get our answer

3.75 x 58.44 = 219.15grams

During lab, you evaluated the bond order and bond length of a series of carbon-carbon bonds. Use the same concepts to predict the bond order and bond length of a series of nitrogen-nitrogen bonds.(a) Which of the structures below have a nitrogen-nitrogen bond order of 3?(b) Which of the structures below have the shortest nitrogen-nitrogen bond?

Answers

Answer:

N≡N

Explanation:

The image attached shows the nitrogen compounds that are being referred to in the question.

There are certain things we ought to know in order to answer the question accurately.

The bond order of a compound is equal to the number of bonds between two atoms. The greater the bond order, the shorter the bond length between the two atoms.

N≡N has a bond order of three, this is the highest bond order among all the species listed in the question. Hence it has the shortest bond length among the trio. Hence the answer.

Coral reefs support more species per unit area than any other marine
environment on Earth. What role do coral reefs play in the health of the
biosphere?
A. Coral reefs tend to drain nearby wetlands of stagnant water.
B. Their productive organisms play a major role in nutrient recycling.
C. Their colorful organisms attract millions of tourists each year.
D. Coral reefs require very specific environmental conditions.
SUBMIT

Answers

Answer:

B. Their productive organisms play a major role in nutrient recycling.

Explanation:

Coral reefs contain photosynthetic algae that help coral reefs in processing nutrients and contribute in the nutrient cycle.

The process of photosynthesis in corals leads to carbon fixing in which corals transform, carbon dioxide, into organic carbon.  carbon fixing property allows corals to become primary producers.

Dissolve organic matter produced by corals is consumed by several organisms such as crabs, worms, fish, and snails.

Hence, coral reefs maintain the flow of energy and nutrient cycle in the biosphere and the correct option is B.

what would happen if you place two positive charges next to each other and let go. would they attract, stay still, or they would repel

Answers

Answer:

they would repel

Explanation:

unlike charges attract while like ones repel.

A student has an unknown sample of solution X. This solution is placed in a 1.00 cm wide cuvet and inserted into the spectrometer, producing an absorbance reading of 0.275 at a wavelength of 525.0 nm. What is the concentration of solution X in the unknown sample

Answers

Answer:

The concentration of the sample is 3.564x10⁻³M.

Explanation:

Using Lambert-Beer law, absorbance of a sample is directely proportional to its concentration.

The general graph of the absorbance of the standards with different concentrations is:

Y = 75.9X + 0.0045

R² = 0.9946

Where Y is the absorbance of the sample and X its concentration in mole/L.

If a solution has an absorbance of 0.275:

0.275 = 75.9X + 0.0045

0.2705 = 75.9X

3.564x10⁻³M = X → The concentration of the sample.

Aspirin is usually packaged with
A. acetic anhydride
B. salicylic acid
C. buffering agents ​

Answers

I believe the answer to s B.

Answer:

Aspirin is usually packaged with C. buffering agents.

Explanation:

g Reduction involves the A) loss of neutrons, gain of electrons, and an increase in oxidation state. B) loss of neutrons. C) increase in oxidation state. D) gain of electrons and an increase in oxidation state. E) gain of electrons.

Answers

Answer:

E. Gain of electrons

Explanation:

A reduction reaction is one part of the two concurrent reactions that take place in a redox (reduction-oxidation) reaction.

During reduction, an atom gains electrons from a donor atom, and it's oxidation number becomes smaller.

Option A is wrong because reduction does not increase oxidation state nor are neutrons involved

Option B is wrong because reduction is not a nuclear reaction (does not involve the nucleons)

Option C is wrong because reduction leads to reduction in oxidation state

Option D is wrong leads to a reduction in oxidation state when electrons are gained

Option E is correct because reduction involves gain of electrons

A maple tree could be studied in many fields of science. What aspects of a maple tree might be studied in chemistry?

Answers

Answer:

Chemical reactions, kinetics, organic chemistry

Explanation:

You might study the chemical reaction, learn about the differences between products and reactants, about delta H and exothermic and endothermic reactions. You may also study Kinetics by studying the rates of reactions with certain chemicals in a maple's enzymatic processes.

Another thing that you might learn about is organic chemistry. The glucose molecules, carbohydrates, lipids, nucleic acids, all have a structure based on the Carbon atom. You can learn about the specific structures of some chemicals that are involved in photosynthesis and simple hydrocarbons that are involved in photosynthetic/bio-synthetic pathways.

There's probably a lot more - but these are the most basic things I could think of.

During which stage of the water cycle could water enter the atmosphere as a gas? A. transpiration B. precipitation C. accumulation D. condensation

Answers

Answer: Transpiration---A

Explanation: Transpiration is the process in the water cycle whereby plant loose(excess) water by evaporation through the stomata of their leaves since not all water absorbed by the root is actually used for growth in plants.In order to allow the intake of carbon-dioxide, water must exit the leaves through transpiration which then  provides the plant with cooling, rigidity and maintaining the overall water balance of the plant.

What kind of solid is crystalline boron (B)?
A. lonic solid
B. Metallic solid
C. Molecular solid
D. Network solid

Answers

Answer:

D

Explanation:

gr. 2.3 at 25°C; valence +3. Boron is a nonmetallic element existing as a dark brown to black amorphous powder or as an extremely hard, usually jet-black to silver-gray, brittle, lustrous, metallike crystalline solid

it is a network solid, a lattice of many covalent bonds (like diamond, except that it is black rather than transparent).

Network solid kind of solid is crystalline boron (B). Hence, option D is correct.

What is Network solid?

A network solid is a solid where all the atoms are covalently bonded in a continuous network.

Boron is a nonmetallic element existing as a dark brown to black amorphous powder or as an extremely hard, usually jet-black to silver-grey, brittle, lustrous, metallike crystalline solid

It is a network solid, a lattice of many covalent bonds (like a diamond, except that it is black rather than transparent).

Hence, option D is correct.

Learn more about Network solid here:

https://brainly.com/question/2700493

#SPJ2

Gravity on Earth is 9.8 m/s2, and gravity on the Moon is 1.6 m/s2.

so if the mass of an object on earth is 40 kilograms what is the mass on the moon.
and how much does it way

Answers

Answer:

Mass is the same but it weights 64 Newtons

Explanation:

First of Mass is the same in any sort of gravity. Now let's calculate weight

W = MG

where W = Weight

M = Mass

G = Gravity

W = (40kg)(1.6)

W = 64

Sorry for the spelling mistakes, hope this helps

Answer:6.61kilo

Explanation: fdfv

Which of the following viewed the atom as having a nucleus made up of protons and neutrons,with electrons orbiting the nucleus in fixed, stable orbits, much like the planets orbit the sun?

Answers

The correct answer is C. Bohr's model

Explanation:

Bohr's model of the atom developed in 1913 proposed each atom contained a nucleus with protons and neutrons. Also, there were electrons that orbited the nucleus. About this, Niels Bohr proposed the orbits of electrons were similar to those of planets around the sun; however, these did not occur due to gravity but to attraction forces. This model integrated new accurate ideas about the atom. However, this model was still inaccurate because particles in an atom are electrically charged and electrons do not orbit in fixed stable orbits and cannot be compared to the movement of planets around a star.  

Answer:

Bohr's model

Explanation:

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