Chemistry question please help

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, all amounts are the same. The correct option is option D.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Calculating the amount of a chemical in grams from moles is among the most often chemistry computations. You will employ the mole ratio of reactants to reagents when balancing equations.

Therefore, all amounts are the same. The correct option is option D.

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Answer:

some animals exhibit structures that are no longer used for any purpose

Explanation:

Vestigial structures are defined as the the organs which are no longer used for any purpose.

Vestigial structures provide evidences of common ancestors as they shows how organisms changed or evolved in the use of these structures. for example: human appendix which is no longer functional in human body but as per Darwin's theory of evolution it was once used by our herbivorous ancestors to protect good bacteria in the gut.

Hence, the correct answer is "some animals exhibit structures that are no longer used for any purpose".

Answer:

A balanced ionic equation shows the reacting ions in a chemical reaction. These equations can be used to represent what happens in precipitation reactions or displacement reactions.

Precipitation reactions

In a typical precipitation reaction, two soluble reactants form an insoluble product and a soluble product.

For example, silver nitrate solution reacts with sodium chloride solution. Insoluble solid silver chloride and sodium nitrate solution form:

AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)

The Na+ ions and NO3- ions remain separate in the sodium nitrate solution and do not form a precipitate. Ions that remain essentially unchanged during a reaction are called spectator ions.This means these can be ignored when writing the ionic equation. Only how the solid silver chloride forms is needed to be shown:

Ag+(aq) + Cl-(aq) → AgCl(s)

In a balanced ionic equation:

the number of positive and negative charges is the same

the numbers of atoms of each element on the left and right are the same

Displacement reactions

Displacement reactions take place when a reactive element displaces a less reactive element from one of its compounds.

A common type of displacement reaction takes place when a reactive metal reacts with the salt of a less reactive metal. For example, copper reacts with silver nitrate solution to produce silver and copper(II) nitrate solution:

2AgNO3(aq) + Cu(s) → 2Ag(s) + Cu(NO3)2(aq)

In this reaction, the NO3- ions remain in the solution and do not react - they are the spectator ions in this reaction. So, they can be removed from the ionic equation:

2Ag+(aq) + Cu(s) → 2Ag(s) + Cu2+(aq)

Question

Explain why this ionic equation is balanced:

Ba2+(aq) + SO42-(aq) → BaSO4(s)

Hide answer

There are the same numbers of atoms of each element on both sides of the equation. The total charge on both sides is also the same (zero).

Question

Balance this ionic equation, which represents the formation of a silver carbonate precipitate:

Ag+(aq) + CO32-(aq) → Ag2CO3(s)

Hide answer

2Ag+(aq) + CO32-(aq) → Ag2CO3(s)

Question

Balance this ionic equation, which represents the displacement of iodine from iodide ions by chlorine:

Cl2(aq) + I-(aq) → I2(aq) + Cl-(aq)

Hide answer

Cl2(aq) + 2I-(aq) → I2(aq) + 2Cl-(aq

Explanation:

this will help, I used this for my work x

AgNO₃ (aq) + NaCl (aq) → AgCl (s) + NaNO₃(aq) is the complete chemical equation taking place between the 2 reactants.

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

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Answer:

Explanation:

Cellular respiration does not depend on light...  Some plants may go into a form of hibernation during winter when the amount of light during the day is less.  The reduction of plant growth and activity would reduce the need for the energy produced by cellular respiration.

Answer:

chemical change

Explanation:

electrolysis process by which electric current is passed through a substance to effect a chemical change.

Answer:

i believe it is a

Explanation:

The reason is :a.They can gain more food for their offspring

Animals tend to protect their territory because they don't want  intruders to invade their territory.

Animals majorly protect their territory in order to protect their foods from been eating by intruders as this will enables their offerings to have enough foods to eat.

They as well guard  their territory in order to prevent intruders from invading the place they have prepare as their mating place.

Inconclusion  The reason why some animals defend  their territory after they have mated

and reproduced is :a.They can gain more food for their offspring

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Answer:

hhmxui

Explanation:

Answer:

15oC to K

oC +273

15+273

288K

Answer: In a chemical reaction, the atoms and molecules that interact with each other are called reactants. ... No new atoms are created, and no atoms are destroyed. In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.

Explanation:

Answer: In a chemical reaction, the atoms and molecules that interact with each other are called reactants. ... No new atoms are created, and no atoms are destroyed. In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.

Explanation: Hope this helped! :)

Answer: There are 113 moles of O in 12.6 moles of [tex]Fe(NO_3)_3[/tex]

Explanation:

Given : moles of [tex]Fe(NO_3)_3[/tex] = 113.4

To find : moles of O = ?

1 mole of [tex]Fe(NO_3)_3[/tex] contains = 9 moles of O atoms

Thus 12.6 mole of [tex]Fe(NO_3)_3[/tex] contains = [tex]\frac{9}{1}\times 12.6=113.4[/tex] moles of O atoms

Thus there are 113 moles of O in 12.6 moles of [tex]Fe(NO_3)_3[/tex]

Answer:

Molecules in the water move in a circular motion

Explanation:

Because of its circular motion it causes the waves to look like open circles which makes it easy for people to surf on

Water molecules move up and forward, down and back, in an overall circular motion in the wave. Therefore, option A is correct.

Circular motion is defined as the movement of an object while rotating in a circle. Circular motion can be uniform or asymmetric.

The angular rate of rotation and speed are constant in uniform circular motion, but the rate of rotation changes in non-uniform circular motion.

This means that circular motion can occur only if there is a "center seeking" force present; otherwise, things will travel in a straight line.

Within the wave, the water molecules move in a circular motion. Each water particle moves in a complete circle during a single wave period. The circle traced by a water particle on the ocean surface as a wave passes a given point has a diameter equal to the height of the wave.

Thus, option A is correct.

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Answer:

look out for a bot with a link he will get yo ip

Explanation:

Answer: It will become solid again and the form of it will change, because when you heat up something you add energy to it. The particles move further and further apart.  

Explanation:

Answer:

21: True

22: False

23: True

24: False

25: False

26: True

27: True

28: False

30: True

Explanation: Hope this is helpful :)

Answer:

this is the answer okkkkkkkkkkkkkkkk

Answer:

Explanation:

The insects have been defined as the most successful arthropods. There are far more species in the class Insecta than in any other group of animals. The insects are the only invertebrates with wings.

The insects play a very important role in the web of the life in every environment. Their jobs include pollinating flowering plants, since it is the source of food for insectivorous animals and it assist in the decomposition of plants and animals.

The two different methods which help to identify the species of the insects from the eggs on human remains are by using a small paint brush dipped in water and the other way is by using the forceps.

The study of insects and their life cycle are found to be important for the forensic entomologist. This is because it could set a timeline on when the crime is happened. The life cycle of a blowfly starts as an egg and then goes to be maggots.

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The transfer of energy between systems through work is the expansion of gas in a steam engine. By doing work or by transferring heat, energy can be transferred. Therefore, option A is correct option.

Energy transfer is a phenomenon in which energy transfer from one matter to another matter. Energy requirement is necessary to move any object so work has to be done by the gas to the piston.

Heat can be transferred by three ways radiation, convention or conduction. In conduction, direct contact of two body is necessary for transfer of molecules. When we touch a shopping cart in the grocery store parking lot, then conduction is the process by which heat is transferred between our hand and the handle.

Therefore, the option A is correct option that is conduction.

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Answer:

CH4 = Methane

CO2 = Carbon dioxide

There are two types of chemical compound one is covalent compound and another is ionic compound in chemistry. In ionic bonds, electrons are completely transferred. Therefore, the name of CH[tex]_4[/tex]  and CO[tex]_2[/tex]  are Methane and Carbon dioxide respectively.

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

Covalent compounds are formed by covalent bond and ionic compounds are formed by ionic bond. Covalent bond is formed by sharing of electron and ionic bond are formed by complete transfer of electron. Ionic bonds are stronger than covalent bonds. The melting and boiling points are higher in ionic compounds.

chemical formula                                      Chemical name

CH[tex]_4[/tex]                                                           Methane

CO[tex]_2[/tex]                                                      Carbon dioxide

Therefore, the name of CH[tex]_4[/tex]  and CO[tex]_2[/tex]  are Methane and  Carbon dioxide respectively.

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Answer:

true

Explanation:

one reason is because plants need sunlight and water because it is their source of food

Answer: I think the answer is B or C, its kind of hard.

As the number of atoms in the water vapor is equal to the number of atoms in the liquid water. Therefore, the mass of the water remains the same.

Evaporation is a process that usually happens on the surface of water or liquid and it involves the conversion of the liquid phase into the gaseous phase. This process involves a change in the state of matter of water or liquids.

When the water is completely evaporated into water vapor the density of the water vapor is less than the density of the liquid water as the vapors occupy a large volume in comparison to liquid water.

But the number of atoms in the water vapor is the same as the number of atoms in the liquid water. The mass of the water is due to the mass of the atoms.

Therefore, the mass of the water remains the same during the phase transition from liquid water to water vapors. Therefore, option (C) is correct.

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Answer:

1, 1, 2

Explanation:

1, 1, 2

Answer:

7. Concave and convex mirrors are called spherical mirrors because they are both made from the sphere. The difference between the two (in the simplest terms) is that diminished images form in convex mirrors while enlarged images form in concave mirrors.

8. The word ambulance is written inverted on an ambulance is because when a driver is driving and sees an ambulance in their rearview mirror, they can see the word ambulance the correct way. Otherwise the word ambulance would be backwards in the mirror. Thats why they write it backwards.

9. A plane mirror forms the image, object, etc, the same exact size that it is. The mirror can be small or large the size of the image will stay the same. So the difference between the object in a small and large plane mirror is none, there is no difference.

10. Car rearview mirrors are curved. This is to give a wider viewing angle. Flat surface mirrors give an accurate reflection. since the rearview mirrors are not flat, they are curved, they are less accurate, so thats why they have a warning label.

11. The sun emits the color of white. And as we know the color white consists of all colors. We can test this by putting the sunlight through a prism. since different colors of light travels at different speeds in the glass we cand see the light 'bent' .

12. Solar cookers use concave mirrors. This is because the mirror reflects the sunlight to a focal, 'center,' point. This center point will eventually heat up very, very hot.

If you have any questions feel free to ask - mark

Answer:

30,000 cm^3

Explanation:

volume for rectangular prism is v=l×w×h

plug in known values and solve.

v=(30.0cm)(20.0cm)(50.0cm)=30,000cm^3

Answer:

33.65%

Explanation:

total weight of solution=14.2+28=42.2g

benzene=14.2/42.2*100=33.65%