In 1909, Ernest Rutherford performed an experiment to explore the atomic structure. In his experiment, he projected high-speed α‎ particles onto a thin gold foil. He found that all α‎ particles did not follow the same path. Most of the particles passed through the foil without any scattering, implying that most of the space in an atom is empty. Some particles were scattered at a large angle, and very few of them scattered back in the direction from which they had come. Based on these observations, Rutherford proposed an atomic model, which is known as Rutherford’s atom.
On the basis of Ruthertord's experimentel observations, which of the following statements describes the structure of the atom according to Rutherford's atomic model?
A. In an aborn, negatively charged electrons are dispersed in the space surrounding tho positively charged nucleus of an atom
B. ln an atom, au of the positive and negative charges are randomly distributed.
C. In an atom, the postive eherges are ocated in a smal core wrin the atom cated the nucleus
D. In an atom, positively charged porticles are dispersed in the space surounding the negiively charged sphere

Answer:

Wind erosion abrades surfaces and makes desert pavement, ventifacts, and desert varnish. Sand dunes are common wind deposits that come in different shapes, depending on winds and sand availability.

Answer:

0.962 atm.

97.4 kPa.

731 torr.

14.1 psi.

97,434.6 Pa.

Explanation:

Hello.

In this case, given the available factors equaling 1 atm of pressure, each required pressure turns out:

- Atmospheres: 1 atm = 760 mmHg:

[tex]p=731mmHg*\frac{1atm}{760mmHg} =0.962atm[/tex]

- Kilopascals:: 101.3 kPa = 760 mmHg:

[tex]p=731mmHg*\frac{101.3kPa}{760mmHg} =97.4kPa[/tex]

- Torrs: 760 torr = 760 mmHg:

[tex]p=731mmHg*\frac{760 torr}{760mmHg} =731 torr[/tex]

- Pounds per square inch: 14.69 psi = 760 mmHg:

[tex]p=731mmHg*\frac{14.69}{760mmHg} =14.1psi[/tex]

- Pascals: 101300 Pa = 760 mmHg:

[tex]p=731mmHg*\frac{101300Pa}{760mmHg} \\\\p=97,434.6Pa[/tex]

Best regards.

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass = 500 g

volume = 11.5 cm³

We have

[tex]density = \frac{500}{11.5} \\ = 43.47826086...[/tex]

We have the final answer as

Hope this helps you

Answer:

2.7 × 10⁶ m

Explanation:

Step 1: Given data

Length: 2.7 × 10³ kilometers

Step 2: Convert "2.7 × 10³ kilometers" to meters

To convert a length from kilometers to meters we need the conversion factor 1 km/1000 m. We will multiply the length by the inverse of this factor so that kilometers are canceled and the final unit is meter.

2.7 × 10³ km × (1000 m/1 km) = 2.7 × 10⁶ m

2.7 × 10³ kilometers is equal to 2.7 × 10⁶ meters.

Answer: 40.496%

Hope this helps! (:

Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question

volume = 22.5 mL

density = 0.23 g/mL

We have

mass = 0.23 × 22.5 = 5.175

We have the final answer as

Hope this helps you

Answer:

Octane is a hydrocarbon and an alkane with the chemical formula C 8 H 18, and the condensed structural formula CH 3 (CH 2) 6 CH 3.Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane) is used as one of the standard values in the octane rating scale.

Chemical formula: C₈H₁₈

Molar mass: 114.232 g·mol−1

Melting point: −57.1 to −56.6 °C; −70.9 to −69.8 °F; 216.0 to 216.6 K

Solubility in water: 0.007 mg dm−3 (at 20 °C)

Answer:

Explanation:

Octane is C8H18, carbon is C. Therefore, for every mol of C8H18 there will be 8 mols of carbon.

Convert 20 kg of octane to mols octane using molar mass of octane.

Molar Mass octane = (8*12.011)+(18*1.008)=114.23 g/mol, where 8 and 18 are the atoms in the molecule and 12.011 and 1.008 are the respective molar masses of carbon and hydrogen.

20kg C8H18 *1000g/kg * mol C8H18/114.23g C8H18 = 175.1 mols octane.

Now convert that number of mols to mols carbon:

175.1 mol C8H18 * (8 mol C/mol C8H18)=1400.8 mol C.

Now remember that a mol of any given atom=6.022*10^23 atoms.

So 1400.8 mol C=1400.8*(6.022*10^23) atoms C, which is equal to your final answer, 8.4*10^26 atoms. (round to 2 significant digits since the initial number given, 20, has 2 significant digits.)

The main thing you want to look for here is your conversion factors. Once you have those down it is simple algebra from there, so be sure to practice those!

Answer:

A. Reference blank

B. Cuvettes

C. Transmittance

D. Absorbance

E. Wavelength

Explanation:

A reference blank is a sample prepared using the solvent and any other chemicals in the sample solutions, but not the absorbing substance.

A square-shaped container, typically made of quartz, designed to hold samples in a spectrophotometer is known as Cuvettes.

A measurement of the amount of light that passes through a sample or percentage of light transmitted by the sample, with the respective intensities of the incident and transmitted beams is called Transmittance.

The measurement of the amount of light taken in by a sample is known as Absorbance

The wavelength is also the distance travelled by the wave during a period of oscillation. In spectrophotometry, the unit is inversely proportional to energy and commonly measured in nanometers

The sample that is prepared using the solvent and any other chemicals in the sample solutions, but not the absorbing substance is a reference blank.

A square-shaped container, typically made of quartz, designed to hold samples in a spectrophotometer is the cuvettes.

A measurement of the amount of light that passes through a sample is transmittance.

A measurement of the amount of light that is taken in by a sample is referred to as absorbance.

A unit that is commonly used in spectrophotometry that is inversely proportional to energy and commonly measured in nanometers is the wavelength.

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Answer:

You can expect the balloon to expand a little

Explanation:

The molecules in the balloon will be heated up once they feel the warmth of the summer heat and start moving a lot faster

Answer:

This question is incomplete

Explanation:

This question is incomplete, however, there are some basic things that be used to answer the completed question on your own. Flame test is a test that is used to identify metal ions in a compound. Although, not all metal ions produce a colour in a flame test.

In a flame test, a "clean wire loop" is dipped in an unknown solid/mixture of solids, the loop where the solids must have attached to is then placed in the tip of a blue flame (perhaps of a bunsen burner). A colour change/changes is then observed during the course of this process. Some popular metal ions and there colour in flame test are listed below

Lithium ion ⇒ red

Sodium ion ⇒ yellow

Potassium ion ⇒ lilac

Calcium ion ⇒ orange-red

Barium ion ⇒ pale-green

Copper ion ⇒ blue-green

rubidium ion ⇒ red-violet

Lead ion ⇒ gray white

The number of different colours observed will ultimately determine the number of elements exposed to the flame

Answer:

D = M/V

Explanation:

D = 55.5g/11.5cm^3

D = 4.83g/cm^3

Answer:

The water is impure

Explanation:

Impurities raises the boiling points and lowers the melting point

Answer:

The answer is in the explanation.

Explanation:

The reaction you want to obtain is:

3C(s) + 4H₂(g) → C₃H₈(g)

The sum of 3(b) + 4(c):

3b. 3C(s) + 3O₂(g) → 3CO₂

4c. 4H₂(g) + 2O₂(g) → 4H₂O(l)

3C(s) + 4H₂(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)

Now, this reaction -(a):

-a. 3CO₂(g) + 4H₂O(l) → C₃H₈(g) + 5O₂(g)

Answer: Grease; Clamp; Ring stand.

Explanation:

Distillation is being used while separating liquids from the nonvolatile solids, or in instance whereby there is a different boiling point between two or more liquids.

Before assembling a distillation apparatus, lubricate the ground glass joints of each piece of glassware using grease. This will help in lubricating the glass joints so that it won't squeeze out while under pressure.

This helps seal the connection between two components. Once two components are fit together, use clamp to make the connections secure. Clamp is a fastening device which will help in holding the components together so that they won't be separated.

Stabilize the complete distillation setup using a ring stand. The ring stand will help in the provision of support to the glassware.

Answer:

An ester of sulfuric acid in which only one sulfuric acid hydroxyl group has been esterified. The product of esterification of both sulfuric acid hydroxyl groups is a sulfate ester.

Answer:

Explanation:

Then, multiply the number of moles of Na by the conversion factor 6.02214179×1023 atoms Na/ 1 mol Na, with 6.02214179×1023 atoms being the number of atoms in one mole of Na (Avogadro's constant), which then allows the cancelation of moles, leaving the number of atoms of Na.Aug 15, 2020

Answer:

1. If an atom of calcium has a mass of 40:

a. Protons = 20

b. Neutrons = 20

2. If an atom of krypton has a mass of 84:

a. Protons = 36

b. Neutrons = 48

3. If an atom of tin has a mass of 119:

a. Protons = 50

b. Neutrons = 69

4. If an atom of tungsten has a mass of 184:

a. Protons = 74

b. Neutrons =110

Answer: B: Iron rusts when exposed to air.

Explanation:

Answer:

B

Explanation:

OB. Iron rusts when exposed to air.

Answer:

Answer choice C

Explanation:

Basicly for the Arrhenius and Bornsted-Lowery theories of acids & bases, acid-base reactions can be divided into 4 forms...

a. Strong Acid + Strong Base (HCl/NaOH) => pH = 7 at Eqv. Pt.

b. Weak Acid + Strong Base (HOAc/NaOH) => pH > 7 at Eqv. Pt.

c. Strong Acid + Weak Base (HCl & NH₄OH) => pH < 7 at Eqv. Pt.

d. Weak Acid + Weak Base (HOAc & NH₄OH) => pH ∝ Stronger Electrolyte

*HOAc = Acetic Acid

*NH₄OH = Ammonium Hydroxide

For each type reaction the pH at equivalence point depends upon the salt generated by the acid-base reaction. Ions of the salt, if they react with water, (hydrolysis) will shift the pH up or down depending upon which ion reacts. If there is no reaction by the salt ions then the pH will depend only upon autoionization of water which gives pH = 7. Typically Strong Acids + Strong Bases will give a pH = 7 at equivalence point because the ions of the salt will not undergo hydrolysis in water.

Example:

Strong Acid + Strong Base

HCl(aq) + NaOH(aq) => NaCl(aq) + H₂O(l)

NaCl(aq) => Na⁺(aq) + Cl⁻(aq)

Na⁺(aq) + H₂O(l) => No Rxn (theoretically NaOH, but NaOH is a strong base which prefers to remain 100% ionized in water).

Cl⁻(aq) + H₂O(l) => No Rxn (theoretically HCl, but HCl is a strong acid which prefers to remain 100% ionized in water).

Therefore, the net rxn is H⁺ + OH⁻ => H₂O & pH = 7.0

Weak Acid + Strong Base

HOAc(aq) + NaOH(aq) => NaOAc(aq) + H₂O(l)

NaOAc(aq) => Na⁺(aq) + OAc⁻(aq)

Na⁺(aq) +  H₂O(l) => No Rxn

OAc⁻(aq) +  H₂O(l) => HOAc(aq) + OH⁻(aq) => (Excess OH⁻ functions to increase pH>7 at eqv. pt.)

Strong Acid + Weak Base

HCl(aq) + NH₄OH(aq) => NH₄Cl(aq) + H₂O(l)

NH₄Cl(aq)  => NH₄⁺(aq) + Cl⁻(aq)

Cl⁻(aq) + H₂O(l) => No Rxn

NH₄⁺(aq) + H₂O(l) => NH₄OH(aq) + H⁺(aq) => (Excess H⁺ functions to decrease pH < 7 at eqv. pt. )

Answer:

When a physical change occurs, the arrangement of particles within the substance may change, but the atoms in the molecules remain bonded together.

Explanation:

Srry didn't see this till now, hope u got it right :)

Answer:

The C-N bond is a double bond.

There is no free rotation about the C-N bond

Explanation:

Linus Pauling and Robert Corey carried out a painstaking study of the bond lengths of peptide bonds as well as the stereo chemistry of atoms and groups around the peptide bonds in the crystal structures of molecules containing one or a few peptide bonds.

Their findings indicate that the bond length of the C-N bond in crystalline peptides is intermediate in length (1.32 Å) between a typical C—N single bond (1.49 Å) and a C=N double bond (1.27 Å). This is because the peptide bond has some double bond character as a result of resonance involving the C=O and -NH moieties of the amide.

As a result of resonance as shown above, the peptide bonds are found to be planar hence free rotation about the C-N bond is hindered. The peptide bond is mostly found in the trans configuration because it is more energetically favourable than the cis configuration.

Summarily, owing to the existence of a partial double bond character between the α carbon and the amine nitrogen in the peptide, there is no free rotation around the C-N bond.

Answer:

[tex]\%Ca=38.76\%[/tex]

Explanation:

Hello.

In this case, since percent compositions are computed by knowing the number of atoms of the required atom, its atomic mass and the molar mass of the compound at which it is, thus, for calcium we have:

[tex]\%Ca=\frac{3*m_{Ca}}{M_{Ca_3(PO_4)_2}} *100\%[/tex]

Thus, since calcium weights 40.08 g/mol and calcium phosphate 310.2 g/mol, the by mass percent of calcium turns out:

[tex]\%Ca=\frac{3*40.08g/mol}{310.2g/mol} *100\%\\\\\%Ca=38.76\%[/tex]

Best regards!

Answer:

elastic potential energy which is also called spring energy.

Answer:

the third one

Explanation:

if you look at it mathematically its the one that makes the most sense

Answer:

Explanation:

The first step in order to solve this particular question is to make sure that the two reactions given in the question is balanced. Therefore, we have;

Reaction 1: C6H12O6 -----------------------------> 2 C2H5OH + 2 CO2.

Reaction 2: C6H12O6 ------------------------------> 2 C2H3CO2H + 2 H2O.

Next, we determine the number of moles of water and that of glucose. Recall that we are given from the question that the open flow reactor =  4000 kg of a 12% glucose-water solution flows in that is to say the percentage for water is [100% - 12% = 88%]. Also, the molar mass of water = H₂O = 18 kg/kmol and that for glucose =180 kg/kmol.

Number of moles of water = (4000 kg × 88%) ÷ 18 = 195.6 kmol.

Number of moles of glucose= (4000kg × 12%) ÷ 180 = 2.67 kmol.

Next thing to do is to determine the number of moles in the unreacted glucose . Therefore, the 90 kg of unreacted glucose ÷ 180kg/kmol = 0.5  kmol.

So, we have that During fermentation, 120 kg of carbon dioxide is produced.  Thus, the number of kmol = 120kg÷ 44kg/mol = 2.73kmol.

For reaction 1, we have 2 moles of CO₂ that is to say the extent of the reaction = 2.73kmol / 2 moles of CO₂ = 1.365 kmol.

For reaction 2, we have 2 moles of CO₂ that is to say the extent of the reaction = 2.67kmol - 0.5  kmol - 1.365kmol = 0.805 kmol.

For both reaction, the kmol for outflow of glucose = 2.73 kmol.

Also, 2 × 0.805 + 1.365 × 0 = 1.61kmol.

Hence, 195.6 kmol + 1.61 =197.21 kmol.

The mass of ethanol = 46.1 kg/kmol × 2.73 kmol = 125.853 kg.

The weight percent of ethanol has been 29.72%, and the percent mass of propionic acid has been 47.79%.

The balanced chemical equations of the reactions have been:

[tex]\rm C_6H_1_2O_6\;\rightarrow\;2\;C_2H_5OH\;+\;2\;CO_2[/tex]

[tex]\rm C_6H_1_2O_6\;\rightarrow\;2\;C_2H_3CO_2H\;+\;2\;H_2O[/tex]

The solution has consisted of 12% glucose.

Water in the solution = 88%

The mass of the solution = 4000 kg.

The moles of glucose = 12% of 4000 kg

Moles of glucose = [tex]\rm \dfrac{12}{100}\;\times\;4000\;\times\;\dfrac{1}{180\;g/mol}[/tex]

Moles of glucose = 2.67 kmol.

Moles of water =  88 % of 4000 kg

Moles of water = [tex]\rm \dfrac{88}{100}\;\times\;4000\;\times\;\dfrac{1}{18\;g/mol}[/tex]

Moles of water = 195.6 kmol.

The unreacted glucose in the mixture = 90 kg

Moles of unreacted glucose:

Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]

Moles of unreacted glucose = [tex]\rm \dfrac{90\;\times\;1000\;g}{180\;g/mol}[/tex]

Moles of unreacted glucose = 0.5 kmol

The mass of carbon dioxide produced = 120 kg.

Moles of carbon dioxide produced = [tex]\rm \dfrac{120\;\times\;1000\;g}{44\;g/mol}[/tex]

Moles of carbon dioxide produced = 2.73 kmol

Since 1 mole of glucose produces 2 moles of carbon dioxide.

2.73 kmol of carbon dioxide has been produced from 1.365 kmol of glucose.

The moles of ethanol produced by reaction 1 = 2 moles/ mole glucose.

The glucose present has been 2.67 kmol.

The ethanol produced = 5.34 kmol.

Moles of propionic acid produced = 5.34 kmol.

The mass of 5.34 kmol ethanol = Moles × molecular weight

The mass of ethanol produced = 5.34 × 1000 × 46.07g/mol

The mass of ethanol produced = 246.0138 kg.

The mass of propionic acid produced = 5.34  × 1000 × 74.08 g/mol

The mass of propionic acid produced = 395.5872 kg.

The mass of water produced = 5.34 × 1000 × 18 g/mol

The mass of water produced = 96.12 kg.

The remained glucose = 90 kg

The total mass in the reactor:

= Mass of glucose + water + propionic acid + ethanol

= 90 + 96.12 + 395.5872 + 246.0138 kg

= 827.721 kg.

% Mass of ethanol = [tex]\rm \dfrac{246.0138}{827.721}\;\times\;100[/tex]

% Mass of ethanol = 29.72%

% Mass of Propionic acid = [tex]\rm \dfrac{395.5872}{827.721}\;\times\;100[/tex]

% Mass of Propionic acid = 47.79 %.

The weight percent of ethanol has been 29.72%, and the percent mass of propionic acid has been 47.79%.

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Answer:

It affects the amount of a species that may be hunted by said predator, controlled you can say.

It can cause evolution in prey that causes them to not be caught, Darwins theory in a way.

Explanation:

Explanation:

At the level of the community, predation reduces the number of individuals in the prey population. The best example of predation involve carnivorous interactions, in which one animal consumes another, Think of wolves hunting moose, owls hunting mice, or shrews hunting worms and insects.