Hydrogen bonding occurs in molecules when a _____________. (1 point)
hydrogen atom forms a covalent bond with one other atom.
hydrogen atom forms covalent bonds with more than one atom.
hydrogen atom of a polarized molecule bonds with an electronegative atom
hydrogen atoms form an ionic bond with one other atom

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.

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

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.

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 : 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)

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

Yeah, it would be that order since if XY was a number, you would multiply it by that number 4 total times. So it would be a large number. And then it gets smaller and smaller when it gets to XY2. So yeah you got the order correct.

Elements are species of atoms that are defined and characterized by the number of protons. The multiple proportions of the element from higher to lowest are XY₄, XY₃, and XY₂.

Elements have been defined as the atomic species that make the molecule and the compounds by combining chemically through bond formation. They are indivisible particles that cannot be broken further.

When two or more elements chemically links then a compound or molecule is formed like element X and Y combined in various ratios and proportions to form XY, XY₂, XY₃, and XY₄.

The highest ratio of the proportions will be XY₄ as it has one X and four Y elements, followed by XY₃ with one X and three Y. Lastly XY₂ will be the lowest ratio as it has one X and two Y elements.

Therefore, the order is XY₄> XY₃ > XY₂.

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

Answer:

The answer is D electrolyte

Explanation:

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!!

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.

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.

1) Answer is: the oxidation number of manganese in MnO₄⁻ is +7.

Permanganate anion has negative charge 1-.

Oxygen (O) in permanganate anion has oxidation number -2.

x + 4 · (-2) = -1.

x - 8 = -1.

x = +7; oxidation nzmber of manganese.

Oxidation number shows the degree of oxidation of an atom in a chemical compound.

2) Answer is: Zn + Cu2+ → Zn2+ + Cu.

In this chemical reaction, there is transfer of electrons from zinc (Zn) to copper (Cu). Zinc change oxidation number from 0 to +2 (lost electrons) and copper change oxidation number from +2 to 0 (gain electrons).

Oxidation half reaction: Zn⁰ → Zn²⁺ + 2e⁻.

Reduction half reaction: Cu²⁺ + 2e⁻ → Cu⁰.

In other chemical reactions, there is no change of oxidation number of elements.

3) Answer is: Br2 is the oxidizing agent because its oxidation number decreases.

Balanced chemical reaction: 2Al + 3Br₂ → 2AlBr₃.

In this chemical reaction, aluminium change oxidation number from 0 to +3 (lose electrons) and bromine change oxidation number from 0 to -1 (gain electrons, reduced).

Oxidizing agent is a substance that has the ability to oxidize other substances, to cause them to lose electrons.

In oxido-reduction reaction, at least one element lose and one element gain electrons.

4) Answer is: Br2 + 2Cl− → Cl2 + 2Br⁻.

Oxidation is increase of oxidation number.

In this balanced chemical reaction, chlorine change oxidation number from -1 (Cl⁻) to oxidation number 0 (Cl₂).

Oxidation half reaction: 2Cl⁻ → Cl₂⁰ + 2e⁻.

Reduction half reaction: Br₂ + 2e⁻ → 2Br⁻.

In other chemical reactions, chlorine is reduced.

5) Answer is: Observation 1 is a result of copper ions moving into the solution.

The reactivity series is a series of metals from highest to lowest reactivity. Metal higher in the reactivity series will displace another.

Copper (Cu) is higher in activity series than silver (Ag), so copper lose electron and silver gain electrons.

Copper is oxidized (increase of oxidation number) and silver is reduced.

Answer:

There's no one-upping that one so I'll just tell you that they were right on my test :)

Explanation:

you're welcome

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.

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:

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.

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.

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.

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

CH4(g) + H2O(g) ---> CO(g) + 3H2(g)

mass of methane CH4 = 256g

molar mass of methane,CH4 = C + 4 H = 16.04g/mol

moles of CH4

= mass/Molar mass

= 256/16.04

= 15.96 moles CH4

moles of H2 produced

= 15.96 moles CH4 x      3 moles H2    

                                           1 mol CH4

=  47.88 moles H2

number of H2 molecules produced here

= 47.88 moles H2 x   6.022 x 10²³ molecules

                                             1 mole

= 288.335 x 10²³ H2 molecules  

=    2.88 x 10²⁵  H2 molecules

2.88 x 10²⁵  H2 molecules are produced when 256g of methane reacts with steam.

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.

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 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.

 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.

  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.

Answer: B) 44.7 g

Explanation:

The equation represent the reaction is

Cl2 + 2NaOH → NaCl + NaClO + H2O

The balanced equation shows that every mole of Cl2 reacts to produce mole of NaClO

0.6 mole of Cl2 will produce 0.6 mole of NaClO

n = mass/molar mass

molar mass of NaClO = 74.5 g/mol

the mass of NaClO = n x molar mass = (0.6 mole) (74.5 g/mol) = 44.7 g

The option, B. Reduced friction means reduced heat transfer " is correct.

Answer:

Reduces friction means increased efficiency

Explanation:

Friction is known to decrease efficiency in machines. In redesigning the engine if the antique car, and the inclusion of oil to reduce friction in the engine, she aims to improve the efficiency of the engine.

Friction leads to lost work in mechanical systems. Friction accounts for the fact that the efficiency of an engine is never 100% since some of the input work is lost as friction.

Hence decreasing the friction improves the efficiency of the machine.

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.  

Some physical properties of matter do not involve a change in state. An example is density, which is an intensive property that does not depend on the amount of matter. It remains consistent regardless of the state of the substance.

Physical properties of matter are characteristics that can be observed without changing the chemical composition of the substance. These properties can often describe changes in state, such as from a solid to a liquid (melting) or a liquid to a gas (boiling). However, there are also other types of physical properties that do not involve a change in state.

One of these physical properties is density. Density does not involve a change in the state of a substance. It is an intensive property, meaning it does not depend on the amount of matter present. It is determined by the mass of an object divided by its volume, and it remains the same regardless of the quantity of the substance you have.

Therefore, Mrs. Green could have been referring to a property like density when she mentioned a physical property that does not describe a change in state.

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Physical properties are characteristics of matter that don't involve a change in the composition of matter. One example is density, which isn't tied to a change of state. Other physical properties include hardness, color, smell, boiling point, and solubility.

When Mrs. Green discusses the physical properties of matter, she is referring to characteristics of matter that are not associated with any change in its chemical composition. Physical properties, such as hardness and boiling point, do not involve a change in the composition of matter, hence they do not correspond to a change of state. An example is the density of a material which remains the same regardless of its state (solid, liquid, or gas). Density is therefore a physical property that does not describe a change in state. Other examples can include color, smell, freezing point, boiling point, and solubility.

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