How many moles are in a sample of 2.39 x 10^23 atoms of sodium (Na)

Answers

Answer 1

Answer:

The answer is 0.4 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\ [/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{2.39 \times {10}^{23} }{6.02 \times {10}^{23} } \\ = 0.39700996...[/tex]

We have the final answer as

0.4 moles

Hope this helps you


Related Questions


A total of eighteen electrons can be placed into the 3rd energy level.
Explain WHY?

Answers

Answer:

each principal energy level above the second contains, in addition to one s orbital and three p orbitals, a set of five d orbitals, called the d sublevel. The five d orbitals can hold up to 10 electrons. Thus, the third level holds a maximum of 18 electrons: 2 in the s orbital, 6 in the three p orbitals, and 10 in the five d orbitals.

Explanation:

What is Arsenic cost per unit?

Answers

Answer:

arsenic costs $320 per 100g

Explanation:

Which element is this.Its shiny,Is solid at room temperature, has atoms with two valence electrons?A:Lithium B:Strontium C:Aluminium D:Silicon

Answers

Answer:

Strontium

Explanation:

STRONTIUM

Strontium is a chemical element that is non radioactive and its occur naturally. It is a shiny and silvery white metal that have atomic number of 38 and it belong to group 2 member of the periodic table which is why it have two valence electrons. It is a solid metal at room temperature.

About 99% of Strontium is found in bones. It help to make new bones in humans by replacing the old bones.

Therefore, it is strontium.

Strontium is the element which is shiny, solid at room temperature and has two electrons in its outermost shell.

The atomic number of Strontium is 38. In the first shell, there are two electrons, in the second and fourth shell has space for 8 electrons so these shells are filled with electron whereas third shell has 18 electrons and the fifth shell has 2 electrons. Strontium belongs to second group i.e. alkaline earth metals due to which it has two valance electrons in its outermost shell.

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.Over a period of 1,000 years, a lake becomes a maple forest. Is this process primary or secondary succession? Explain your answer.

Answers

Answer:

It is secondary succession.

Explanation:

primary succession only occurs in areas where there was no previous ecosystem

In the production of maple forest over the 1,000 years period, there has been the presence of the lake. Thus the production in the lake has been the secondary succession.

The primary and secondary succession has been the development process in the ecosystem. The ecosystem development can be taken place when there has been no previous vegetation, or when there has been the available ecosystem.

The primary succession can result when there has been no available previous ecosystem. The secondary succession can take place when there has been a previously existing ecosystem.

In the production of maple forest over the 1,000 years period, there has been the presence of the lake. Thus the production in the lake has been the secondary succession.

For more information about succession, refer to the link:

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the ability for a substance to rust is
a. oxidation
b.rustability
c.magnetic attraction
d.reactivity

Answers

Answer:

i think it is letter b. rustability but not so sureeee

Suppose you wanted to calculate the heat of reaction for the formation of ammonia gas and hydrochloric acid from solid ammonium chloride. Write a balanced equation for this reaction

Answers

Answer:

NH4Cl (s) → NH3 (g) + HCl (aq)

HELP ASAPP JUST TELL ME WHAT TO PUT IN THE MISSING SPACES words(cell,microorganisms,micrometer,microscopic,molecule)

Answers

Answer:

microorganisms, molecule, microscopic, cell, micrometer

Explanation:

If you find my answer helpful

Pls consider marking it as Brainliest! It would mean a lot!

1. A pile of boxes exerts a force of 500 newtons downward on the floor. The boxes are not in motion. What is the normal force on these boxes?

2. Norman drags a stubborn dog by his leash with a force of 200 newtons. The dog is slowly moving towards Norman. What do you know about the force exerted by the dog?

3. A baby grand piano sits in a music room. The piano exerts a force of 3500 newtons downward. Isaac tells his friends that he is strong enough to lift the piano off the floor. How much force will he have to use to lift the piano?

4. Ms. Holt is dragging a box of assessments across the floor using a force of 70 newtons. The frictional force acting against the box is 50 newtons. What is the net force on the box?

5. A bicycle is sitting motionless in the driveway. What is the net force acting on this bike?

6. Maria drops a box that exerts of force of 300 newtons downward on a table. The normal force acting on the box from the table is 250 newtons. What will happen to the table and the box? What is the net force of the box?

7. Anna is riding her bike, moving at a constant velocity of 3 miles per hour to the south. She is using 200 N of force to pedal her bike. A gust of wind blowing in the same direction she is traveling suddenly exerts a force of 20 Newtons on her. What will happen to her motion? (hint: Use the term accelerate OR decelerate in your answer.)

8. Mrs. Fedde is riding her bike, moving at a constant velocity of 5 miles per hour to the north. She is using 300 N of force to pedal her bike. A gust of wind blowing in the opposite direction she is traveling suddenly exerts a force of 50 Newtons on her. What will happen to her motion? (hint: Use the term accelerate OR decelerate in your answer.)

Answers

5000 for sure hope this helps you

A student observes that instant tea dissolves more rapidly in a cup of 250 mL of stirred hot water than in a cup of 250 mL of stirred cold water. Which is the most relevant hypothesis that the student could develop based on this observation?

A.
Volume affects the rate that instant tea dissolves in a solvent.
B.
Temperature affects the rate that instant tea dissolves in water.
C.
Stirring affects the rate that instant tea dissolves in water.
D.
Pressure affects the rate that instant tea dissolves in water.

Please answer my question!

Answers

Answer:

B

Explanation:

In this question, there is no mention of pressure, so we can eliminate answer D. In both cups, it mentions they contain 250 mL of water and both are stirred, so these would be constants. The only difference between the cups is temperature, so temperature must affect the rate that instant tea dissolves in water. Therefore the answer is B.

A piece of metal is composed of atoms Each atom in the metal contains 29 protons how is the metal classified

Answers

Answer:

you an see the answer at the pic

[04.01] Which best describes the transition from gas to liquid?​

Answers

Answer:

When gaseous state changes into liquid state the molecules slow down in speed because of decrease in energy molecules come slightly closer to each other.

Please answer it correctly and explain clearly

Answers

Answer:

i think that the children will inherit the brown eyes, it is the best answer since the other things cant be inherited and he dyed his hair blonde

Explanation:

List the steps of how a virus is able to infect your cells

Answers

Answer:

Key Points

Viral replication involves six steps: attachment, penetration, uncoating, replication, assembly, and release.

During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it.

7. Which liquid caused the egg to shrink? *
(1 Point)
a. Vinegar
b.Water
c.Corn Syrup

Answers

Answer:

c.corn syrup

the egg shrinks due to osmosi.

It’s corn syrup Bec it can’t go into the egg

How do you think changes in temperature can cause movement of air and other fluids on Earth?

Answers

Where on Earth's surface might you be if you are experiencing the trade winds? Explain how air pressure, temperature, and the Coriolis effect in movement and direction of thesewinds.

""The polar easterlies"-is dry and cold prevailing winds that blow from the high pressure areas of the polar highs at the north and south poles towards low pressure areas within the Westerlies at high latitudes.

Cold air  diminish at the pole making the high  force, Pushing an equator-ward discharge, of air; that outflow is then Sidetrack westward by the Coriolis effect."

Hoped This Helped,  

Your Welcome :)

Which of these statements about density is NOT true? a The density of a block of substance A equals 10.0 g/cm3. If I cut the block in half, its density will equal 10.0 g/cm3. b A cubic meter of bricks is more dense than a cubic meter of feathers. c It is possible to identify a substance by its density. d The density of a substance is always the same, regardless of temperature.

Answers

Answer:

d. The density of a substance is always the same, regardless of temperature.

Explanation:

Density is a characteristic property of water and defined as the mass per unit volume.

The density of a substance always remains the same at the same temperature regardless of the size of the sample. The density of the sample changes with temperature and pressure. for example : The density of a substance increases with a decrease in temperature as the volume increases.

Hence, the statement about density is not true is " d. The density of a substance is always the same, regardless of temperature."

What happens to the particles of a liquid when energy is removed from them?

A. The motion of the particles increases and the distance between the particles increases.

B. The motion of the particles increases and the distance between the particles decreases.

C. The motion of the particles decreases and the distance between the particles increases.

D. The motion of the particles decreases and the distance between the particles decreases.

Answers

Answer:

b im pretty sure it is  b

Explanation  b  The motion of the particles increases and the distance between the particles decreases.

The motion of the particles decreases and the distance between the particles increases, the correct option is C.

What are different states of matter?

The matter is anything that has mass and occupies space.

Matter can exist in four different states: solid, liquid, gas, and plasma.

By examining the arrangement of molecules, it is possible to comprehend the characteristics of the many forms of matter.

The state of a solid turns to a liquid when it is heated past its melting point.

A liquid turns into a gas when it is heated past the point at which it vaporizes.

Solids have a distinct shape and dimension and are densely packed.

Liquids fill the container's space and are loosely packed.

Gas has a large intermolecular distance and is not stiff.

When energy is removed from the particles of a liquid, the speed gets slowed, and so the motion decreases, as the motion is limited they become packed and the distance between them decreases, and the intermolecular forces increases.

To know more about Different states of matter

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Identify the choice that best completes the statement or answers the question.
Banana slugs live on the ground in moist forests of the Pacific Northwest. They consume and
break down a variety of materials, including small dead animals and rotting leaves. Which
term describes banana slugs?
O carnivores
O consumers
O decomposers
O producers
PLEASE HELP!!!

Answers

The answer would be decomposers

what is the mass of 10 moles of helium​

Answers

Answer:

The mass of 10 moles of helium is: 2.5

If an animal is placed into a sealed container for a short time, the oxygen level will
A. decrease and the carbon dioxide level will increase.
B. decrease and the carbon dioxide level will decrease,
C, increase and the carbon dioxide level will increase.
D. decrease and the carbon dioxide level will stay the same.
E increase and the carbon dioxide level will decrease.

Answers

Answer:

A

Explanation:

Animals take in oxygen and convert it into carbon dioxide therefore the oxygen levels will decrease and the carbon dioxide levels will increase

If an animal is placed into a sealed container for a short time, the oxygen level will:  decrease and the carbon dioxide level will increase.

What happens to oxygen level inside a container:

The oxygen held inside the space is quickly being consumed by the freight or because of rusting inside a space, and that encased spaces must consistently be treated as perilous. And the carbon dioxide levels on the other hand will increase.

It will not take a long time for an animal to survive under these conditions.

Thus. option A is correct.

Find more information about Oxygen here:

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Calculate the number of molecules of sulphur S8 in 8 gram of solid Sulphur​

Answers

Answer:

12gram

Explanation:

test told me

Electrons will pair up in an orbital only when

Answers

Answer:

All orbitals in the same sub level have one electron

Explanation:

All orbitals in the same sub level have one electron

what mass of gold, Au, contains the same number of atoms as 9.0 g of aluminum Al

Answers

Answer:

55.16 grams of gold contain same number of atoms as 7.72g AI contain

Part 1 Designing an Investigation
Melinda was cooking a pizza and removed the pizza from the
oven, which was set to 400 degrees Fahrenheit. She wanted to
cool down the pizza as quickly as possible to eat it. In her house,
she had a freezer (set to 0 degrees Fahrenheit), a refrigerator
(set to 40 degrees Fahrenheit), and the countertop (which is at
the temperature of the room, 78 degrees Fahrenheit).
1. Design an experiment that will let Melinda study which of
the three options, the refrigerator, the freezer, or the room, will let the pizza cool down the fastest.
Experimental Question (How does (IV) the heat
affect the pizza to cool down
DV)
Independent Variable
Dependent Variable
Experiment Plan

Answers

Answer:

The experimental plan is to measure the values of the dependent variable, which is the temperature of the pizza after it is cooled in each of the heat (temperature) environments, which is the dependent variable, for a given equal period of time, which is the control

Explanation:

The given parameters are;

The temperature of the pizza = 400°F

The temperature of the freezer = 0°F

The temperature of the refrigerator = 40°F

The temperature of the countertop = 78°F

Given that the independent variable = The heat to which the hot pizza is subjected

The dependent variable = The temperature to which the pizza cools down

The experiment plan includes;

1) Place the pizza which is at 400°F in each of the different heat environment, which are, the freezer, the fridge, and the counter top, for the same period of time and record the final temperature of the pizza

2) The option that gives the lowest final temperature within the same time frame is the option that will let the pizza cool down fastest.

What do Lucille's cells need in order for her body to function properly? How might a problem with Lucille's respiratory system lead to low levels of oxygen in her cells? Why does having low levels of oxygen in her cells make it difficult for Lucille to play soccer?

Answers

Answer:

In order for her body to act correctly, Lucille's cells require glucose and oxygen. A problem with Lucille's respiratory system leading to low levels of oxygen in her cells is known as Hypoxemia. Having low levels of oxygen in her cells will make it difficult for Lucille to play soccer because she would not be able to breathe .If her respiratory system doesn't function properly, so enough oxygen molecules will not move into her respiratory system , ensuring that her cells won't have enough oxygen molecules. Playing soccer is difficult if you don't have enough air.

Explanation:

ABOUT HYPOXEMIA -: It is called hypoxemia to have low oxygen levels in your blood. It is called hypoxia to have insufficient oxygen levels in the tissues. Hypoxemia at high altitudes can occur. Hypoxemia that induces low levels of oxygen in the tissues of the body is called hypoxia. The two words are often used by people interchangeably, but they are not the same thing.

The capacity of the body to supply normal amounts of oxygen to the blood can interfere with a number of conditions and circumstances. Some of hypoxemia's most prevalent causes include:

Heart problems, heart defects included  .Lung disorders such as asthma , bronchitis, emphysema. High-altitude areas where oxygen is lower in the air.  Powerful drugs for pain or other conditions that delay respiration . Sleep apnea (breathing impairment during sleep)  .Lung tissue inflammation or scarring (as in pulmonary fibrosis).

Answer:

In order for her body to act correctly, Lucille's cells require glucose and oxygen.

A problem with Lucille's respiratory system leading to low levels of oxygen in her cells is known as Hypoxemia.

Having low levels of oxygen in her cells will make it difficult for Lucille to play soccer because she would not be able to breathe .If her respiratory system doesn't function properly, so enough oxygen molecules will not move into her respiratory system , ensuring that her cells won't have enough oxygen molecules. Playing soccer is difficult if you don't have enough air.

Explanation:

ABOUT HYPOXEMIA -: It is called hypoxemia to have low oxygen levels in your blood. It is called hypoxemia to have insufficient oxygen levels in the tissues. Hypoxemia at high altitudes can occur. Hypoxemia that induces low levels of oxygen in the tissues of the body is called hypoxia. The two words are often used by people interchangeably, but they are not the same thing.

The capacity of the body to supply normal amounts of oxygen to the blood can interfere with a number of conditions and circumstances. Some of hypoxemia's most prevalent causes include:

Heart problems, heart defects included  .

Lung disorders such as asthma , bronchitis, emphysema.

High-altitude areas where oxygen is lower in the air.  

Powerful drugs for pain or other conditions that delay respiration .

Sleep apnea (breathing impairment during sleep)  .

Lung tissue inflammation or scarring (as in pulmonary fibrosis).


What is the one way that the thermal energy of a system can be explained?

Answers

Answer: here is 1 way:

Explanation:

Meh explaination :1. Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. A whole branch of physics, thermodynamics, deals with how heat is transferred between different systems and how work is done in the process (see the 1ˢᵗ law of thermodynamics).

Easy explaination:2. The energy of motion in the molecules of a substance.

Hard explanation: 3. Thermal energy is defined as the total of all kinetic energies within a given system.

Hope this helps!;)

An object with a mass of 1.2 g takes up a space of 2.4 mL. What is it's density?

Answers

Answer:

The answer is 0.5 g/mL

Explanation:

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

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

From the question we have

[tex]density = \frac{1.2}{2.4} \\ [/tex]

We have the final answer as

0.5 g/mL.

Hope this helps you

The formula for density is almost always expressed as grams per milliliter in chemistry. To find the density of this object, simply divide the number of grams by the number of milliliters.

Therefore, we get:

1.2g / 2.4 mL = 0.5g/mL

This results in a density of 0.5g/mL!

Do 2. A student determines that there are 1.3 x 1025 molecules of an unknown
substance in a 968 g sample. Which compound most likely represents this
unknown substance?
CO
CIO
2)
CO2
N203
CLEAR ALL

Answers

Answer:

The correct option is;

CO₂

Explanation:

The given information are;

The number of molecules in the substance = 1.3 × 10²⁵

The mass of the substance = 968 g

Therefore, we have;

The number of molecules in one mole of a substance = 6.02 × 10²³

The number of moles present = (1.3 × 10²⁵)/(6.02 × 10²³) ≈ 21.595 moles

Therefore, 968 g = 21.595 moles

1 mole = 968/21.595 = 44.826 g

The mass of one mole of the substance = 44.826 g

Therefore the mass of one mole of the substance is closely related to the mass of one mole of CO₂ which is 44.01 g/mol.  

The correct option is CO₂

The calculation is as follows:

The number of molecules in one mole of a substance should be = 6.02 × 10²³

And,

The number of moles present is

= (1.3 × 10²⁵)/(6.02 × 10²³)

≈ 21.595 moles

Now

1 mole = 968/21.595 = 44.826 g

The mass of one mole of the substance = 44.826 g

So,  the mass of one mole of the substance is closely related to the mass of one mole of CO₂ i.e.  44.01 g/mol.  

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What is the decomposition of 2LiCIO3

Answers

Decomposition is AB —> A + B

2LiClO3 —> 2LiCl + 3O2

What is the Independent and Dependent Variables for this experiment?
"How does the amount of salt in water affect how an egg floats?"
please help!!

Answers

Answer:

The egg is the dependent variable and the salt is the independent variable.

Explanation:

The dependent variable is something that stays the same throughout the experiment. The independent variable is something that might not stay the same throughout the experiment. The egg does not change because we're using an egg and not an egg and then a tomato or a potato, but the salt does change because we're changing the amount of salt in the bowl/plate or anything else that we are using to perform this.

This is kinda long but it explains mostly everything. DM me for more dependent and independent variable help.

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Skidmore Music Company had the following transactions in March:a. Sold instruments to customers for $16, 700, received $10, 700 in cash and the rest on account. The cost of the instruments was $7, 100.b. Purchased $4, 900 of new instruments inventory; paid $1, 700 in cash and owed the rest on account.c. Paid $720 in wages for the month.d. Received $3, 100 from customers as deposits on orders of new instruments to be sold to the customers in April.e. Received a $280 bill for March utilities that will be paid in April.Required:Complete the following statements:1. Cash basis Income Statement2. Accrual basis Income Statement what is a unit of electrical flow called Image courtesy of NASAWhich two bodies of water are connected by the Suez Canal on the map above?A. Letter A and Letter BB. Letter B and Letter CC. Letter C and Letter ED. Letter D and Letter E Read this excerpt from "Life Without Go-Go Boots" by Barbara Kingsolver and answer the question.We lived in the country, in the middle of an alfalfa field; we had no immediate access to Bobbie Brookssweaters. I went to school in the hand-me-downs of a cousin three years older. She had excellent fashionsense, but during the three-year lag her every sleek outfit turned to a pumpkin.2 ... My black lace-up oxfords,which my parents perceived to have orthopedic value, carried their own weight in the spectacle. I suspectedpeople noticed, and I knew it for sure on the day Billy Stamps announced to the lunch line, "Make way for theBride of Frankenstein."4Which of the numbered sentences from the excerpt shows the most commentary and why?1 - says something about family's social and economic status2 - is about fairy tales3- is about medical value of shoes4- quotes popular culture Which of the following must be in place for observational learning to occur? A) Retention and multiple attempts at success B) Attention to model and motivation to imitate C) Attention to instructor and making connections D) Motivation and lack of basic necessities Mark randomly chose a snack, replaced it, and then chose another snack. What is the probability that Mark chose a bag of chocolate and then chose a bag of dried fruit? Larkspur Incorporated factored $124,300 of accounts receivable with Cullumber Factors Inc. on a without-recourse basis. Cullumber assesses a 2% finance charge of the amount of accounts receivable and retains an amount equal to 5% of accounts receivable for possible adjustments. Required:Prepare the journal entry for Larkspur Incorporated and Cullumber Factors to record the factoring of the accounts receivable to Cullumber. After Auschwitz: 3. Imagery consists of descriptive words and phrases that create sensory experiences for the reader. Wiesel writes: Here heaven and earth are on fire. What image is he communicating? What effect does it have on the reader? SOMEONE HELP ME PLSSSSSS PLSSS In the first part of the story, readers learn about characters, setting, and plot through the narrators exposition. The second part of the story depends mostly on dialogue to advance the plot. How does this change affect the pacing and mood of this part of the story? Which is the better buy, 6 bagels for $3.29 or 8 bagels for $4.15? Justify your answer. What is the percent error for the experiment if the actual density is2.49g/mL but the experimental value is 1.47 g/mL? Convert the number to scientific notations 89,970,303,001= The Mesopotamians started settling near the two rivers, Euphrates and Tigris. Explain TWO reasons why they settled near the rivers and how this helped the development of their civilization. (Think about how and for what did they used these two rivers) * Simplify the expression.74(32) A. 218 B. 218 C. 76 D. 76 Type the integer that makes the following addition sentence trueBlank + (-8) = -2 what is 9999x9999 hahhahahahhahahahahaha Gail Martinez is employed at My Best Books. She has family medical coverage through the group medical plan that My Best Books provides for its employees. The annual cost of Martinez's family membership is $3,900. The company pays 50% of the cost. How much does she pay annually for medical insurance? * Ask a question in response to each statement about Camille and Lola's new apartment. **Use qu'est-ce que or que.MODLE: Nous visitons le logement de Camille et Lola. -Qu'est-ce que vous visitez? (ou Que visitez-vous?)Please help?! HELP FAST !!! plzzzzz you are about to go to school when your mother asked you to stay at home and take care of your baby brother/ sister