The molarity (M) of an aqueous solution containing 15.6 g of sucrose, C12H22O11, in 65.5 mL of solution is:

6.96 x 10–4 M.

2.47 x 10–2 M.

0.696 M.

1.33 M.

Answer is: D) Light is emitted from an atom as an electron falls from an excited state to the ground state releasing a photon.

Electrons can jump from one energy level to another, absorbing or emitting electromagnetic radiation with a frequency ν (energy difference of the levels).

When electron jump from higher to lower energy level (shell), it emitting (releasing) energy.

For example, when the electron changes from n=4 (fouth shell) to n=2 (second shell), the photons are emitted.

Albert Einstein (1879-1955) proposed that a beam of light is a collection of discrete wave packets (photons) with energy hν, where h is Planck constant and ν is frequency.

The photons have a characteristic energy proportional to the frequency of the light.

Minimum frequency or the threshold frequency is energy below which no photoelectrons are emitted.  

Above the minimum frequency, energy depends on the frequency of the light, not on the intensity of the light.

Answer:

3 mol Cl₂/2 mol AlCl₃ (three over two)

Step-by-step explanation:

Start with the balanced equation"

2Al + 3Cl₂⟶ 2AlCl₃

The steps in the calculation are

mass of AlCl₃ ⟶ moles of AlCl₃⟶ moles of Cl₂ ⟶ mass of Cl₂

The critical step is the conversion of moles.

You multiply the moles of AlCl₃ by a conversion factor to get moles of Al:

Moles of AlCl₃ × conversion factor = moles of Al.

The conversion factor is the molar ratio, and it uses the coefficients of the formulas in the balanced equation.

It is either (2 mol AlCl₃/3 mol Cl₂) or (3 mol Cl₂/2 mol AlCl₃).

You choose the one that has the desired units of the answer in the numerator.

We choose the second option, because it has the correct units.

For example,

[tex]\text{0.2 mol AlCl}_{3} \times \frac{3\textbf{ mol Cl}_{2} }{ 2\text{ mol AlCl}_{3} } = 0.3\textbf{ mol Cl}_{2})[/tex]

Notice how the units "mol AlCl₃" cancel and the correct units appear in the answer.

If we had used the other conversion factor, we would have gotten the wrong units.

Stimulants often cause overactive eye movement

Ans (A)

Stimulants are a class of psychoactive drugs that increase the brain activity. They work by acting on the central nervous system and increase the level of mental alertness and impart heightened cognitive functions. Stimulants like nicotine and cocaine cause overactive eye movement.

Answer:

( A). Stimulants is a correct answer.

Explanation:

Stimulants result in the overactive movement of eye.

Stimulants belong to the class psychoactive drugs which cause increase brain function.

Stimulants results in the change of the corneal curvature, and it increases the alertness and energy for a limited period of time.

Ritalin is a class of stimulants known as Methylphenidate and other stimulants like nicotine, cocaine result in overactive movement of the eye.

In this condition, people are not able to concentrate on multiple visual works at the same time.

Answer : The correct option is, (A) Equilibrium shifts right to produce more product.

Explanation :

According to the Le Chatelier's principle, when we are adding or removing the products or reactants from the reaction, the equilibrium will shift towards that side where the less number of molecule.

The given equilibrium reaction is,

[tex]2H_2S\rightleftharpoons 2H_2(g)+S_2(g)[/tex]

In the given reaction, when we are removing the hydrogen gas from the reaction then the equilibrium will shift towards the right side to produce more product.

Hence, the correct option is, (A)

No work is done on the box as Aru holds and walks with it because the force he applies is perpendicular to the displacement, resulting in zero work according to physics principles.

The question asks us to calculate the work done on a box that is being held and carried over a certain distance. According to the definition of work in physics, work is done when a force causes a displacement in the direction of the force. In this case, Aru is holding a 4 newton box and walking for 2000 meters, but since the force he exerts is perpendicular to the displacement (holding the box does not cause it to move vertically), no work is done on the box in terms of physics.

If the force is perpendicular to the displacement, as it is in Aru's case, this results in zero work being done on the object because the force does not contribute to the displacement in any way.

An example of calculating work done is when a force is applied in the direction of the displacement. For instance: If a force of 10 newtons (F = 10 N) is applied in the direction of displacement and the object moves 2 meters (d = 2 m), then the work done (W) would be calculated as W = F × d, which means W = (10 N)×(2 m) = 20 Joules.

The correct answer is ionic radii increase.  

The ionic radii decrease as one move across the periodic table, that is, from left to right, while the ionic radius increases as one move from top to bottom on the periodic table. As one moves down a group in the periodic table, the supplementary layers of electrons are being added that usually results in the increase of the ionic radius as one moves down the periodic table.  

Balanced chemical reaction happening here is:

3Mg(s) + N₂(g) → Mg₃N₂(s)        

 moles of product formed from each reactant:

2.0 mol of N2 (g) x 1 mol Mg₃N₂        = 2 mol Mg₃N₂

                                    1 mol N2

and

8.0 mol of Mg(s) x 1 mol Mg₃N₂         = 2.67 mol Mg₃N₂

                                 3 mol Mg

Since N2 is giving the least amount of product(Mg₃N₂) ie. 2 mol Mg₃N₂

N2 is the limiting reactant here and Mg is excess reactant.

Hence mole of product formed here is 2 mol Mg₃N₂    

molar mass of Mg₃N₂    

= 3 Mg + 2 N

= 101g/mol  

mass of product(Mg₃N₂) formed  

= moles x Molar mass

= 2 x 101

= 202g Mg₃N₂

202g of product are formed from 2.0 mol of N2(g) and 8.0 mol of Mg(s).

    The following are indicators of chemical changes:

Change in Temperature    

Change in Color

Formation of a Precipitate

Answer : The correct option is, (C) a positive calcium ion and a negative oxygen ion.

Explanation :

Ionic compound : ionic compounds are the compounds which are made up of positively charged cation and the negatively charged anion. The bond form between the cation and anion is known as ionic bond.

For example : NaCl, LiF, NaBr, etc.

In option C, a positive calcium ion combine with a negative oxygen ion to give calcium oxide. So, these two particles can form an ionic bond with each other.

While the other options A, B and D can not form an ionic bond with each other.

Therefore, the correct option is C.

It threatens local industries. This is because local industries are smaller in scale than the industries that have international reach. The local industries cannot compete with the international industries because they cannot keep their prices as competitive because they lack economies of scale.

Answer is: the total number of electrons shared between the atoms is four.

Molecule of oxygen is nonpolar because double linear bonds (O=O).

Oxygen (O) is an element with atomic number 8, it means it has eight protons and eight electrons, so atom has neutral charge. Oxygen is a nonmetal.

Electron configuration of oxygen atom: ₈O 1s² 2s² 2p⁴.

Oxygen atom has six valence electrons, so it is in 16 group of Periodic table of elements.

Two valence electrons from both oxygen atoms form double bond (O::O) at oxygen molecule.

Answer:

Formula for oxygen is [tex]O_{2}[/tex] and total number of electrons shared between the atoms are 4

Explanation:

Oxygen is a diatomic molecule. Hence two oxygen atoms combine to produce one oxygen molecule.

Now, number of valence electron in a oxygen atom is 6. So total number of valence electrons used to form oxygen molecule are 12.

To draw a Lewis structure for [tex]O_{2}[/tex], octet rule should be fulfilled by both oxygen atoms.

According to octet rule, an atom should have 8 electrons in its valence shell

Lewis structure for oxygen molecule has been attached below.

Here electrons shared by oxygen atoms are represented as vertical line. These are called bonding electrons.

Unshared electrons are represented by dot. These are called lone pairs.

Here one bond is formed by sharing two electrons.

As there are two bonds between two oxygen atoms therefore total number of shared electrons between oxygen atoms are 4.

I think the anwer is electrolyte :)... i had it on a test a couple days ago.

Answer:

The answer is D electrolyte

Explanation:

 Lets find the electronegativity difference between the bonded atoms;

C-H = 2.6-2.2 = 0.4

C-F = 4.0-2.6  = 1.4

F-F = 4.0-4.0   = 0

H-O = 3.4-2.2  = 1.2

Here the electronegativity difference is highest for C-F bond hence C-F bond is most polar.

The correct answer is intertidal zone.

The littoral zone or the intertidal zone, also known as the foreshore or the seashore, refers to the area, which is above the water at low tide and below the water at high tide. This zone incorporates different types of habitats, with animals like starfish sea urchin, and various species of coral. This zone is situated close to the coastlines of all the continents.

Answer: shallow ocean

Explanation:

shallow near the coastlines

only one that could make sense

Final answer:

The name for the S²⁻ anion is the sulfide ion, which is derived from the stem name of sulfur with the suffix '-ide' added, followed by 'ion'.

Explanation:

The S²⁻ anion is known as the sulfide ion. When sulfur gains two electrons, it forms a negatively charged ion with 18 electrons and 16 protons, resulting in a 2- charge. According to the nomenclature for monatomic anions, the name of the ion is derived from the element's stem name, with the suffix '-ide' added, and then followed by the word 'ion'. Therefore, the name for S²⁻ is 'sulfur' + '-ide ion', which gives us sulfide ion.

A mole of water is 18 g. This is the molar mass of H2O (16 for O plus 2 for 2 H).

So In 2.5 g you have 2.5/18 Moles of water. 2.5/18 * Avogadro constant gives you the number of molecules. This should be 8.37 x 10^22 molecules. Good luck!!

The correct answer is that a chemical bond formed when two atoms share electrons is called a Covalent Bond, though this option is not provided in the question. This type of bond is exemplified by the bonding in a hydrogen molecule (H2).

The question seems to have a typographical error. It appears to be asking about a certain type of chemical bond, specifically one formed when two atoms share electrons. However, none of the answer choices appear to correctly describe this type of bond. The appropriate response for a chemical bond that involves sharing of electrons would be a Covalent Bond. A typical example of this would be the bonding between two Hydrogen atoms in a H2 molecule, where they share their singular electron to fulfil their respective octet.

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  1.The balanced  chemical equation is as below

Cu +  2 Ag(NO)₃ → Cu(NO₃)₂  +2 Ag

2.The  much silver  produced  is  50.9 g

Step 1: find the  moles of Cu

moles =  mass÷  molar mass

  from periodic table the molar mass of Cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236  moles

Step 2: use the mole ratio to determine the  moles of Ag

from equation above   Cu:Ag  is 1:2

therefore the moles of Ag   =0.236  moles  x 2/1 =0.472  moles

Step 3: find the mass  of Ag

mass = moles x molar mass

from periodic table  the molar mass of Ag =107.87 g/mol

mass  = 0.472  moles x 107.87 g/mol = 50.9 g

3.  The  much  silver  collected worth is  1.797 oz

 convert  50.9 g  to oz

that is  1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1  gram}  =1.797 oz

The amount of silver produced from 15.00 grams of copper is approximately 50.97 grams. The value of this silver is  [tex]$7.995.[/tex]

The answer to the question is as follows:

 1. The balanced chemical equation for the reaction between copper metal and silver nitrate is:

[tex]\[ \text{Cu}(s) + 2\text{AgNO}_3(aq) \rightarrow \text{Cu(NO}_3)_2(aq) + 2\text{Ag}(s) \][/tex]

 2. To find out how much silver is produced when 15.00 grams of Cu is added to the solution, we first need to use the molar mass of copper to convert grams of copper to moles. The molar mass of copper (Cu) is approximately 63.55 g/mol.

[tex]\[ \text{Moles of Cu} = \frac{\text{Mass of Cu}}{\text{Molar mass of Cu}} = \frac{15.00 \text{ g}}{63.55 \text{ g/mol}} \approx 0.236 \text{ mol} \][/tex]

 From the balanced equation, 1 mole of Cu produces 2 moles of Ag. Therefore, the moles of Ag produced are:

[tex]\[ \text{Moles of Ag} = 2 \times \text{Moles of Cu} = 2 \times 0.236 \text{ mol} \approx 0.472 \text{ mol} \][/tex]

The molar mass of silver (Ag) is approximately 107.87 g/mol. We can now convert the moles of Ag to grams:

[tex]\[ \text{Mass of Ag} = \text{Moles of Ag} \times \text{Molar mass of Ag} = 0.472 \text{ mol} \times 107.87 \text{ g/mol} \approx 50.97 \text{ g} \][/tex]

3. To find out the value of the silver produced, we need to convert grams of silver to ounces and then multiply by the price per ounce. The conversion factor is 1 gram = 0.0353 ounces.

[tex]\[ \text{Ounces of Ag} = \text{Mass of Ag} \times \text{Conversion factor} = 50.97 \text{ g} \times 0.0353 \text{ oz/g} \approx 1.799 \text{ oz} \][/tex]

 Now, we multiply the mass of silver in ounces by the price per ounce to find the value:

[tex]\[ \text{Value of Ag} = \text{Ounces of Ag} \times \text{Price per oz} = 1.799 \text{ oz} \times \$4.50/\text{oz} \approx \$7.995 \][/tex]

Therefore, the silver collected would be worth approximately $7.995.

 In summary, the balanced chemical equation for the reaction is:

[tex]\[ \text{Cu}(s) + 2\text{AgNO}_3(aq) \rightarrow \text{Cu(NO}_3)_2(aq) + 2\text{Ag}(s) \][/tex]

The amount of silver produced from 15.00 grams of copper is approximately 50.97 grams. The value of this silver is approximately $7.995.

  The charge that  alkali metal   form  when they  involve in a chemical reaction with non metals  is  1+

 Explanation

Metals react   by   losing  electron to form a positively charged   ion.

 Alkali metal   has   1  electron  in outermost   sub shell  which  is donated  when they react with non metals  to form  ions with a charge of 1+.

For example sodium (Na)  metal with [Ne] 3S¹   electron configuration   donate  the  1 electron   in outermost subshell (3S) to form Na⁺ ion.

The mixture was stirred and the precipitate was collected, dried carefully, and weighed. The grams of precipitate should be obtained is 2.53 g. Hence option B is correct.

Mixture is defined as a material composed of two or more chemical compounds that do not chemically combine together. Mixtures are classified into two types: heterogeneous and homogeneous. Heterogeneous mixtures have distinct components, whereas homogeneous mixtures appear uniform throughout.

[tex]\rm K_2CrO_4(aq) + BaCl_2(aq) \rightarrow BaCrO_4(s) + 2KCl(aq)[/tex]

Moles of K₂CrO₄ = Molarity x Volume

                            = 0.200 x 0.100

                            = 0.02 moles

Moles of BaCl₂ = 0.1 x 0.100

                         = 0.01 moles

Moles of BaCrO₄ = 0.01 moles

Mass of BaCrO₄ = 0.01 x 253

                           = 2.53 grams.

Thus, the mixture was stirred and the precipitate was collected, dried carefully, and weighed. The grams of precipitate should be obtained is 2.53 g. Hence option B is correct.

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Answer:

Fractional Distillation

Explanation:

Fractional distillation is a type of separating technique used to separate constituents of a mixture (miscible) with varying boiling points. In fractional distillation, heat is applied to the mixture and the constituent with the least boiling point vaporizes out first, then the one with the next boiling point follows (the jars used to obtain the constituents will be changed at different boiling points) and the one with the highest boiling point is obtained last. Alcohol/ethanol has a boiling point  of 78°C while water has a boiling point of 100°C hence after exposure to heat, ethanol evaporates out first (and then cooled outside the distilling flask; in a condenser, so it can be converted back to liquid). Since we have just two constituents in this mixture, only water will be left in the distilling flask at about 85°C.

The order from longest to shortest wavelength is;

Radio wave  (longest wavelength)

Microwave

Infrared

Red visible

Orange visible

Yellow visible

Green visible

Blue visible

Violet visible

Ultraviolet (UV)

X-ray

Gamma radiation (shortest wavelengths)

This is referred to as the electromagnetic spectrum.

The EM radiation types ordered from largest to shortest wavelength are: Radio wave, Microwave, Infrared, Red visible, Orange visible, Yellow visible, Green visible, Blue visible, Violet visible, Ultraviolet (UV), X-ray, and Gamma radiation.

To place the various types of electromagnetic (EM) radiation in order from largest wavelength to shortest wavelength, we'll refer to the relationship between wavelength, frequency, and energy of EM waves. As the wavelength decreases, both the frequency and energy increase. Here's the correct order from largest to shortest wavelength:

Within the visible light spectrum, remember ROY G BIV as a mnemonic to order the colors from longest (red) to shortest (violet) wavelengths. Beyond the visible spectrum, infrared radiation has longer wavelengths than visible red light, whereas ultraviolet light, X-rays, and gamma rays have shorter wavelengths than visible violet light.

The answer is B as going from left to right on the periodic table elements increase by 1 in valence electrons

Valence electrons : The electrons on the outermost shell

1a) Answer is: the number of moles of gold (Au) in the sample is 0.178 mol.

m(Au) = 35.12 g; mass of gold.

M(Au) = 196.97 g/mol; molar mass of gold.

n(Au) = m(Au) ÷ M(Au).

n(Au) = 35.12 g ÷ 196.97 g/mol.

n(Au) = 0.178 mol; amount of gold.

1b) Answer is: the number of atoms of gold (Au) is 1.073·10²³.

N(Au) = n(Au) · Na.

N(Au) = 0.178 mol · 6.022·10²³ 1/mol.

N(Au) = 1.073·10²³.

2a) Answer is: 0.0035 moles of sucrose.

m(C₁₂H₂₂O₁₁) = 1.202 g; mass of sucrose.

M(C₁₂H₂₂O₁₁) = 12 · Ar(C) + 22 · Ar(H) + 11 · Ar(O) · g/mol.

M(C₁₂H₂₂O₁₁) = 12 · 12.01 + 22 · 1.01 + 11 · 16 · g/mol.

M(C₁₂H₂₂O₁₁) = 342.3 g/mol; molar mass of sucrose.

n(C₁₂H₂₂O₁₁) = m(C₁₂H₂₂O₁₁) ÷ M(C₁₂H₂₂O₁₁).

n(C₁₂H₂₂O₁₁) = 1.202 g ÷ 342.3 g/mol.

n(C₁₂H₂₂O₁₁) = 0.0035 mol; amount of sucrose.

2b) n(C) = 12·n(C₁₂H₂₂O₁₁).

n(C) = 12 · 0.0035 mol.

n(C) = 0.042 mol; amount of carbon in sucrose.

n(H) = 22·n(C₁₂H₂₂O₁₁).

n(H) = 22 · 0.0035 mol.

n(H) = 0.077 mol; amount of hydrogen in sucrose.

n(O) = 11·n(C₁₂H₂₂O₁₁).

n(O) = 11 · 0.0035 mol.

n(O) = 0.0385 mol; amount of oxygen atoms in sucrose.

2c) N(C) = n(C) · Na.

N(C) = 0.042 mol · 6.022·10²³ 1/mol.

N(C) = 2.53·10²²; number of carbon atoms in sucrose.

N(H) = n(H) · Na.

N(H) = 0.077 mol · 6.022·10²³ 1/mol.

N(H) = 4.63·10²²; number of hydrogen atoms in sucrose.

N(O) = n(O) · Na.

N(O) = 0.0385 mol · 6.022·10²³ 1/mol.

N(O) = 2.31·10²²; number of oxygen atoms in sucrose.

Na is Avogadro constant.

Answer: the substance dissolves

Explanation: Chemical change is the change in which chemical composition of the substance changes.

Chemical changes are accompanied by following changes:

a) formation of precipitate

b) release or absorption of energy

c) formation of gas

d) change in color

When a substance dissolves, it only changes its state and thus there is no change in chemical composition.

Answer: Option (d) is the correct answer.

Explanation:

A chemical change is defined as the change that results in the formation of new compounds due to change in chemical composition of reactants.

For example, when any two aqueous solutions chemically react with each other then it results in the formation of an insoluble solid that is known as a precipitate.

Also, a gas is released when two substances chemically react together.

It is known that in an exothermic reaction heat is released. So, when a container gets hot then it means two or more substance have chemically react together due to which an exothermic reaction has taken place.

On the other hand, when no change in chemical composition of reactants occur then it means no chemical change has taken place.

For example, when NaCl is dissolved in water then it dissociates into sodium and chlorine ions.

This means no new compound has formed. As by evaporating water, crystals of NaCl can be formed again.

So, when a substance dissolves in water then it means no chemical change has taken place unless and until a new compound is not formed.

Thus, we can conclude that the substance dissolves is not an indication of a chemical change.

Answer:

The correct statement is :When the volume of a gas decreases, the pressure increases.

Explanation:

Main point of kinetic matter theory:

When we increase the pressure of  the on the particles of matter the space between them will get decrease due to which attractive force between the particles will also get increase by which they will come closer and result in decrease in volume of the matter.

Here you go !!!!! envelope, cutting and sewing instructions, tissue pattern pieces

The half life of an isotope means how long it will take for the amount of given isotope to decay to only 1/2 of the original amount.

If you start with 10.0g of polonium-218 and the half life is 3.0 minutes, then in 3.0 minutes you will have half of the original amount

Half of the original amount is equal to 5.0g

The answer is 5.0g

It will take 3.0 minutes for the amount of polonium-218 to decrease from 10.0 g to 5.0 g, corresponding to its half-life duration.

The question is about the half-life of polonium-218, which is a Chemistry concept dealing with the radioactive decay of isotopes. The half-life is the time required for half of the radioactive nuclei in a sample to decay. In this case, we're asked to find out how long it takes for a 10.0 g sample of polonium-218 to decay to 5.0 g. Because the half-life of polonium-218 is given as 3.0 minutes, it will take exactly one half-life period for the amount of polonium-218 to decrement from 10.0 g to 5.0 g.

Therefore, it will take 3.0 minutes for half of the initial sample to remain, going from 10.0 g to 5.0 g.