Why do we need to build models of molecules to study atomic composition?

Answers

Answer 1

Answer:

for better understanding and visual understanding


Related Questions

What is the volume of 0.1 M HCl required to neutralize 12.0 mL of 0.25M
Ba(OH)2?

Answers

Answer:

15ml

4HCl + 2Ba(OH)2 so moles ratio is 4:2

Certain __________ metals like gold are found as pure metals rather than ores in the earth. Complete the sentence.

Answers

Answer:

nonreactive

Explanation:

When 0.717 g of sodium metal is added to an excess of hydrochloric acid, 7450 J of heat are produced. What is the enthalpy of the reaction as written?

2Na(s)+2HCl(aq)⟶2NaCl(aq)+H2(g)

Answers

Answer:

The enthalpy change of the reaction is 4.78 × 10⁴ J.

Explanation:

We are given that 0.717 g of sodium metal reacts with hydrochloric acid to produce 7450 J of heat.

Converting grams of sodium to moles:

[tex]\displaystyle 0.717 \text{ g Na} \cdot \frac{1 \text{ mol Na}}{22.99 \text{ g Na}} = 0.0312 \text{ mol Na}[/tex]

And dividing the amount of heat produced by the moles of sodium reacted yields:

[tex]\displaystyle \Delta H = \frac{7450 \text{ J}}{0.312 \text{ mol Na}} = 2.39 \times 10^4 \text{ J/mol Na}[/tex]

Because the given reaction has two moles of sodium metal, we can multiply the above value by two to acquire the enthalpy change of the given reaction:

[tex]\displaystyle \Delta H = 2\text{ mol Na}\left(2.39 \times 10^4 \text{ J/mol Na}}\right) = 4.78 \times 10^4 \text{ J}[/tex]

In conclusion, the enthalpy change of the reaction is 4.78 × 10⁴ J.

Balance the equation
Ca(s) + H3PO4(aq) ---->Ca3(PO4)2(s) + H2(g)

Answers

Answer: CO2x+O4H I don’t know if this is the right answer

What kind of wave causes particles in rocks to move at right angles to the direction of the wave

Answers

Answer:

Secondary waves

A type of seismic body wave in which rock particles vibrate at right angles to the direction of wave travel. Secondary waves cause the rocks they pass through to change in shape.

A transverse wave is a wave in which particles of the medium vibrate at right angles, or perpendicular, to the direction that the wave travels.

A chemist makes up a solution by dissolving 42.0 g of Mg(NO3)2 in enough water to produce a final solution volume of 213 mL. To calculate the molarity of the solution, what additional information is needed

Answers

Answer:

the molar mass of Mg(NO3)2

the mass of the water added the density of the Mg(NO3)2

the volume of water used

Calculate the number of moles of Mg(NO3)2 used to make up this solution. 42.0 g of Mg(NO3)2 is equivalent to___ mol Mg(NO3)2.

Now calculate the molarity of the solution, giving your answer to the correct number of significant digits.

Molarity of Mg(NO3)2 = ___M

Hey! Help please :)

Answers

Answer:

6. 15 oxygen atoms (The coefficient 5 is multiplied by the subscript 3 of oxygen)

7. The number "2" is the subscript.

PLEASE ANSWER ASAP!!!
The movement of tectonic plates in two different locations is shown below:

Two blocks labeled Location A and Location B are shown. The block labeled A has a vertical line in the middle. On the left of the line there is an arrow pointing down. On the right of the vertical line there is an arrow pointing up. At Location B the top layer of the block shows two horizontal arrows pointing towards each other. The portion of this block on the right is shown moving down.
Which statement is most likely true?

Subduction occurs in both locations.

The magnetic orientation of rocks may change in Location A and subduction occurs in Location B.

Subduction occurs in Location A and the magnetic orientation of rocks may change in Location B.

Answers

Answer: its a and b

Explanation:its very simple and the reason is bc yea

Answer:

B

Explanation:

The answer is B because it said subduction i guess. And I got it right! Hope this helps to anyone that is looking at this!

The
is the wind system responsible for the movement of weather from west to east across most of the continental United States
A

polar easterlies

B


prevailing westerlies

C


trade winds

Answers

Answer:

Westerlies are prevailing winds that blow from the west at midlatitudes. They are fed by polar easterlies and winds from the high-pressure horse latitudes, which sandwich them on either side.Nov 15, C answer

All participants in the Genius dog challenge are border collies which some experts think are the what breed of dog?

Answers

As far as the intelligence of canines, it is widely accepted as a fact that the Border Collie is the most intelligent breed of dog.

The conclusion that border collies are the most intelligent breed of dog is credited to a canine psychologist by the name of Stanley Coren. He studied over 138 recognized breeds of dogs to measure the ease with which they learned new commands and the obedience rate of each breed.

Coren studies the learning and obedience of Border Collies over the course of 199 trials and found that this breed of dog performed 95% better than most other breeds, with only 9 of the 138 breeds studied coming close to the results of the border collie. Easily earning the title of the most intelligent breed of dogs.

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how many grams of C2H5OH would get if you started with 5.0 g

Answers

Answer:

92.13688 grams

Plants exchange carbon dioxide, water, and oxygen with their surrounding environment through openings in their ________ called _________.
A.
leaves, xylem
B.
roots, guard cells
C.
leaves, stomata
D.
stems, sori

Answers

C. Leaves and Stomata
the answer to this is c as there are openings in leaves!

How many moles of NH3 can be produced from 5.50 moles of nitrogen in the following reaction: N2+3H2=2NH3

Answers

Answer:

Explanation:

Let the molar balance numbers be your guide.

N2 has  a one in  front of  it.

2 NH3 has a two in front of it.

Nitrogen has 5.50 moles given.

1 / 5.50 = 2 / x                 Cross multiply

1 x  = 2 * 5.50

x = 11.0

So if you use 5.5 moles of nitrogen, you get 11 moles of NH3

When the concentration of SO2(g) is increased to 1.48 M, the ratio of products to reactants is 1.4. The equilibrium constant for the reaction is 14. In which direction will the reaction shift to regain equilibrium

Answers

Answer:

Towards the products

Explanation:

The equilibrium constant for the reaction is 14. The equilibrium will shift towards the product.

What is equilibrium?

Equilibrium is defined as a condition in which the forward and backward reaction rates are identical. When all of the external forces acting on an object are balanced, the object is said to be in equilibrium in a reference coordinate system. This indicates that all external forces and moments acting on this item have a net effect of zero.

When sulfur dioxide SO2 concentration is increased, the Q value rises to 1.4.

Q = [ SO₃ ]² / [ SO₂ ]² [ O₂ ]

Q = 1.4

Where K

K = [ SO₃ ]² / [ SO₂ ]² [ O₂ ]

K = 14

Q will shift to the right to consume the extra SO2 and restore the equilibrium position since Q is less than K.

Thus, the equilibrium constant for the reaction is 14. The equilibrium will shift towards the product.

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Identify the general features of an amino acid. Which part is responsible for the unique properties of each amino acid

Answers

Answer:

Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. This R group, or side chain, gives each amino acid proteins specific characteristics, including size, polarity, and pH.

Explanation:

The R group is another atom or group of atoms that is attached to the core atom in every amino acid. This R group, or side chain, provides each amino acid protein with unique properties such as size, polarity, and pH.

Amino acids are chemical molecules that are used to construct proteins. Proteins are vital macromolecules in living organisms, serving a variety of functions including enzymatic catalysis, structural support, transportation, immunological response, and others. A polypeptide chain is formed by linking amino acids in a precise sequence, which subsequently folds into a three-dimensional structure to make a functioning protein.

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Help with this pretty please!

Answers

Answer:

10

Explanation:

Basically same as last question but the number is before the compound :)

PLEASE HELP
1. A closed bottle contains a mixture of Ar and O2 at 25.3°C. If the partial pressure of Ar in
the bottle is 0.447 atm and the total pressure of the bottle is 1.024 atm, what is the partial
pressure of O2 in the bottle?

Answers

Answer: 0.79 atm

Explanation:

The Ideal Gas Law is PV=nRT.

since both Ar and O2 have the same volume and temperature, the only variable causing the differnce in pressure betwwen the 2 gases is the number of moles

the total pressure = the partial pressure of Ar + the partial  pressure of O2

1.024 atm = 0.447 amt + ?

so  

? = 1.24 -0,447 = 1.24 - 0.45= 0.79 atm

the total pressure of the bottle is 1.024 atm, what is the partial

pressure of O2 in the bottle? is PV

Methane (CH4) is used in laboratory burner. When 1 mole of methane burns at constant pressure, it produces 804 kJ of heat and does 3 kJ of work.Methane (CH4) is used in laboratory burner. When 1 mole of methane burns at constant pressure, it produces 804 kJ of heat and does 3 kJ of work.

Answers

The enthalpy ΔH of combustion is - 804 kJ. The change in internal energy ΔE of the reaction process is -801 kJ

The objective of this question is to determine the value of ΔH and ΔE of combustion is for 1 mole of methane.

If we look closely at the question, we will realize that at constant pressure, methane burns and produces heat of 804 kJ into the surroundings.

Since heat is released;

ΔH = -804 kJ

It also does a work of 3kJ, since work is done on the system

W = - 3kJ

According to the first law of thermodynamics;

ΔE = ΔH  -  W

ΔE = (-804 - (-3 )) kJ

ΔE = -801 kJ

Therefore, we can conclude that the in 1 mole of methane, the enthalpy ΔH of combustion is - 804 kJ. The change in internal energy ΔE of the reaction process is -801 kJ

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Most chloride salts are soluble. Which of the following is an exception to this generalization?
A. NH4Cl
B. AlCl3
C. ZnCl2
D. CuCl2
E. PbCl2

Answers

The exception to the rule concerning the solubility of chlorides in water is PbCl2.

The solubility rules give us an idea of which substances are soluble in water and what substances are not soluble in water. According to the solubility rules, chlorides are soluble in water.

However, chlorides of lead are not soluble in water hence, the exception to the rule is PbCl2.

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From the options given, the chloride salt that is not soluble is PbCl₂.

Solubility simply means the ability of liquid, solid, or gaseous chemical substance to be bake to dissolve in solvent and then form a solution.

It should be noted that most chloride salts are soluble. Examples include NH₄Cl, AlCl₃, ZnCl₂, CuCl₂, etc. However, the chloride of lead aren't soluble in water. Therefore, PbCl₂ isn't soluble in water.

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Write and balance the equation for the complete combustion of heptane, C7H16. Phase symbols and energy changes are optional.

Answers

The balanced equation for the complete combustion of heptane, [tex]C_{7}H_{16}[/tex] is given as,

[tex]C_{7}H16(g) + 11O_{2} (g)[/tex] → [tex]7CO_{2}(g) + 8H_{2}O(g)[/tex] + heat/light

What is combustion reaction?It is exothermic redox chemical reaction.The reaction between fuel and oxidant to produce oxidized product is called combustion reaction.The oxidant are usually atmospheric oxygen.The oxidized product is carbon dioxide gas and water.

What is balanced chemical equation?

The chemical equation in which number of atom each elements is equal in reactant and product of the reaction is called  balanced chemical equation.

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20 points! Please Help!!

Based on what you have read what is the opportunity cost of the glass-making company's decision?
a higher quaity tem
a greater proft
a loss of equipment
a longer production time​

Answers

Answer:

a greater profit......

Explain how chemical spills on a person are handled when they are spilled :
(a) over the body
(b) in the eyes

Answers

A). Remove contaminated clothing, shoes, jewelry and your laboratory coat. Ask someone in the laboratory to assist you.
Immediately flush the area with copious amounts of water for at least 15 minutes. If your eyes do not require flushing, attempt to protect the eyes from cross contamination.
Seek medical attention after washing the affected area for 15 minutes and call 911 or go to the nearest emergency care facility.
B). Don't rub the eye — this may cause further damage.
Don't put anything except water or contact lens saline rinse in the eye. And don't use eyedrops unless emergency personnel tell you to do so. Flush your eye with water. Use clean, lukewarm tap water for at least 20 minutes.

(50 POINT) use this to answer: https://phet.colorado.edu/sims/html/acid-base-solutions/latest/acid-base-solutions_en.html

Describe how you could adjust the settings of the simulation to increase the number of red (H3O+) and blue (A-) particles in the solution of equilibrium. In three to four sentences, justify your answer and explain how and why this would change the pH of the solution.

Answers

The addition of more acid or base will increase the number of H3O+ and A- particles thereby decreasing and increasing the pH of the solution respectively.

What is an acid-base titration?

An acid-base titration is one in which an acid is added to a given volume of base in order to neutralize it.

When more of acid is added to a solution of a base than is required to neutralize it, the solution becomes acidic.

Similarly, when more base is use to neutralize an acid than is required, the solution becomes alkaline.

In the given simulation, (H3O+) is the acid while (A-) is the base.

By adding increasing the quantity of acid added, the number of H3O+ particles will increase. This will reduce the pH of the solution.

Also, the adding more base to the solution, the number of A- particles in the solution will increase. This will increase the pH of the solution.

Therefore, addition of more acid or base will increase the number of H3O+ and A- particles thereby decreasing and increasing the pH of the solution respectively.

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Is there a need for adhesives?

Answers

Answer:

yes

Explanation:

what would happen if the next time you needed tape or glue you remember, oh wait theres none at the house, thats just an example of why you would indeed need adhesives

(20 points) In the morning, you decide to make toasted bacon, lettuce, and tomato sandwich. Observe what happens in each stage of making the sandwich. Which parts involve only chemical changes happening?

I. The first thing you do is cut two slices of bread.
II. Then you put the slices in the toaster to cook. When the toaster is done, it pops the III. warm brown toast. You cook the bacon in a frying pan you put bacon, lettuce, and tomato on the bread, trimming the sides.
IV. You can smell the old bread in the garbage going moldy.

Steps I and II
Steps II and III
Steps II and IV
Steps III and IV

Answers

Answer:

C is the answer I did it and got it right

Two students are identifying a sample of tap water.
Student A says that tap water is a mixture, while
Student B says that it is a compound. Which student
is correct? Justify your answer.

Answers

Tap water is a mixture not compound due to presence of many substance.

Tap water is an example of mixture not compound because in tap water, water is not available in pure form, it has many substances mix with water and those substances make no bond with water.

It has dissolved compounds like calcium carbonate, magnesium and fluoride. Different elements or compounds are physically combined rather than chemically linked together so we can conclude that student A is correct that tap water is a mixture.

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A bike with mass of 10 kg is moving with a speed of 5 m/s. What is the magnitude of its momentum?​

Answers

Answer:

The momentum is then (10 kg)(5 m/s)= 490.5 kg-m/s

Explanation:

Answer is A

1) When a beam of white rays is dispersed by a prism which colour will be refracted to a larger extent?

Answers

Explanation:

since diferentes colours of light través at diferentes speeds, the refractiva index is diferentes for each color. The result? that whenthe White light países thought the prism it cover into a red light

Hi I of the following compounds is an aldehyde?

Answers

Answer:

cpd 2

Explanation:

aldehyde is such a cpd which contains an alkyle gp with the formula R-CH=O

Functional group can be interconverted into each other by the means of suitable reagent. Functional group are responsible for the chemical and physical properties of a compound. Therefore the correct option is option 2 that is having group  R-CHO.

What is functional group?

A group of atoms forming a component of a molecule that accounts for a particular function or chemical behavior is called a functional group. There are so many functional group in organic chemistry.

The list of functional groups with their corresponding formulas can be given as

Carboxylic group COOH

Alcoholic group OH

Ammine group NH₂

Ketonic group R-CO_R

Aldehydic group R-CHO

Thiol group R-S-H

Cyanide group -CN

Therefore the correct option is option 2 that is having group  R-CHO.

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Hey :3 please help with this. Will mark brainlist if you’re right

Answers

Answer: 4

Explanation:

Other Questions
Whats the answer need in 20 minutes Name the three common states of matter on earth.Which states of matter have a set shape? Explain why this is, based on the animations you observed for the different states of matter.Which states of matter have a set volume? Explain why this is, based on the animations you observed for the different states of matter.The boiling point is the temperature at which a liquid substance will turn to vapor, and also the temperature at which vapor will condense to a liquid. The boiling point of ethanol is about 80C, and the boiling point of water is about 100C.What can you conclude about the intermolecular forces in water and ethanol?Do you predict water freezes at a higher temperature or at a lower temperature than ethanol?Recall how different Van der Waals attractions and how ionic charges changed the movement of atoms in the animation. Do you think that Van der Waals attractions or ionic charges are stronger? Why?1. solid, liquid and gas2.Solid can move but gas and liquid is more flexible than solid. Solid has a fixed volume while liquid and gas takes the volume of its container. Solid stays in one place while gas and liquid is flexible.3.Among the 3 state, solid has a fixed volume while liquid takes the volume of its container. When gas is compressed, it takes the volume of its container likewise. Your deductible expenditures are $8236 for interest on a home mortgage, $3528 for contributions to charity, and $634 for state income taxes. Your filing status entitles you to a standard deduction of $12,200. Should you itemize your deductions rather than claiming the standard deduction? If so, what is the difference? Your 12 turkeys drink 7.6 L of water a day. Howmuch water does one turkey drink per day? Find the greatest common factor of 21 and 46. Find the distance between stress also affects _________________ and is influenced by self-care matters such as diet and exercise and organizational issues like time management. stress can cause more than just a bad day. A cab company charges a $3 boarding rate in addition to its meter which is $2 for every mile. What is the equation?Please give an actual answer NO LINK SPAM OR REPORT: Tell whether x and y show direct variation. Explain your reasoning. If so, find k.xy=0 1. Hydrogen and nitrogen combine to form ammonia. When nitrogen and hydrogen bond, nitrogen pulls the electrons from hydrogen toward itself. Which statement about the reactants is correct?A) Hydrogen is oxidized, and nitrogen loses electrons.B) Hydrogen is oxidized, and nitrogen is reduced. C) Hydrogen gains electrons, and nitrogen is reduced. D) Hydrogen is reduced, and nitrogen is oxidized. 2. Which phrase best defines a redox reaction? A) A reaction in which the number of oxygen atoms is reduced. B) A reaction in which elements are transferred between different atoms. C) A reaction is which oxygen combines with different atoms. D) a reaction in which elements are released from the system. 3.Which statement describes the process of oxidation? A) Oxidation results in a loss of electrons, so the oxidation number increases. B) Oxidation results in a gain of electrons, so the oxidation number increases.C) Oxidation results in a gain of electrons, so the oxidation number decreases. D) Oxidation results in a loss of electrons, so the oxidation number decreases. 4. Which chemical equation represents a redox reaction? A) TiCl4(s) + 2H2O(g) TiO2(s) +4HCl(g)B) CaO(s) + SiO2(s) CaSiO3(l)C) CaCO3(s) CaO(s) + CO2(g) D)Fe2O3(s) + 2Al(s) Al2O3(s) +2Fe(l)5. Which elements are oxidized and reduced in the reaction below? Br2 (l) + 2NaI(aq) I2 (s) + 2NaBr(aq)A) Bromine (Br) is oxidized, and iodine (I) is reduced. B) Iodine (I) is oxidized, and bromine (Br) is reduced.C) Sodium (Na) is oxidized, and bromine (Br) is reduced.D) Bromine (Br) is oxidized, and sodium (Na) is reduced. A farmer uses two types of fertilizers. A 50lb bag of fertilizer A contains 6 lb of nitrogen and 3lb of phosphorus. A 50 lb bag of fertilizer B contains 4 lb each of nitrogen and phosphorus. The minimum requirements for a field are 480 lb of nitrogen and 240 lb of phosphorus. If a 50lb bag of fertilizer A costs $35 and a 50 lb bag of fertilizer B costs $25 find the amount of each type of fertilizer the farmer should use to minimize his cost while still meeting the minimum requirements. mathematically formulate and state the problem. Why do you think tribal people resisted conversion to Christianity Answer Asap! find the equation of the line passing through (3,-6) with the gradient of -1/2 Why do you think people lack micronutrients? help me urgent thankyouu Which of the following occurred under the Abbasid Caliphate (750 CE)? A. Rome was named the capital. B. Cairo was named the capital. C. Baghdad was named the capital. D. Mecca was named the capital. The Killer ClownsOne dark and stormy night, a loud bang came from the garage. A 10 year old girl named Rosa went to see what it was. When Rosa opened the door the lights went out. She knew there was a flashlight near the door, but she couldnt find it, and the breaker-box was on the other side of the house in the basement. Suddenly the lights started to flicker on and off. She heard footsteps coming down the hall. Rosa ran and hid is a closet across the hall, she whispered to herself Please dont come this way. Clump, Clump, Clump She heard the footsteps getting closer, all of a sudden they stopped in front of the door and went back down the hall. Rosa let out a sigh of relief. Then she heard a clown car and thought Thats odd, clown cars dont pass through this late but realized there were killer clowns on the loose and the police couldnt stop them, the clowns already killed the entire police force. She knew what she had to do. The kitchen was down the hall and it sounded like the intruder was upstairs in the attic. Rosa had found a bag and started towards the kitchen, she knew exactly where the kitchen knives were and grabbed some food and a large carving knife. She also grabbed her mothers pistol and some ammo from the gun safe. She heard the front door rattling and knew to get to her room, because it was her and her puppy, Rose-Bud who was a pit bull, that night and it had no windows to get in through.Rosa locked the room door and pushed the dresser and nightstand against the door to barricade the door. Rosa heard the honking of a rubber chicken, and she knew the clowns were here. Still instead of screaming she stayed silent, got the gun loaded and ready to fire then hid in her closet. She would be safe in there for the time being, suddenly she knew Chuckie had teamed up with the killer clowns. Who else would have the clowns teamed up with besides a haunted doll? Rosa heard a knife scraping against the wall, it was deafening. Rosa was still in her closet with Rose-Bud. Bang, Bang, Bang went the door, a clown had gotten in! The clown opened the closet door very slowly and got shot straight in the heart. The gunfire made Chuckie and all the clowns run, but they are still out there. Innovative team firms should have managers who provide ________, ________, and perspective to the team. What is the value of the first term in an=n+6?