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

One way to separate the different kinds of matter in a mixture is through


A. filteration
B. decomposition
C. electrolysis
D. chemical reactions

Answers

The answer is filtration (A).

Creating a mixture is a physical process; as such, the substances that make up a true mixture do not undergo any chemical reactions with one another. It follows, then, that to separate substances that are mixed together, the process to use would be physical, not chemical. Filtration fits that bill: Solutes that do not dissolve in the solvent can be trapped, for example, by a fine mesh whose openings are large enough for the solvent to pass through but too small for the undissolved solute(s) to do so.

Choices B, C, and D are all chemical processes.

Decomposition (B) is the breakdown of a substance into chemically distinct fragments. For example, hydrogen peroxide in a mixture (solution) with water decomposes in the presence of an appropriate catalyst—the products you are left with are water and oxygen gas, which bubbles out of the mixture. But you haven’t separated the hydrogen peroxide from the water—through decomposition, the hydrogen peroxide molecules are broken up and the atoms rearranged to form different molecules. There’s no hydrogen peroxide left to separate anymore. So, decomposition doesn’t separate different substances in a mixture—it transforms them.

Electrolysis (C) is a chemical process that uses an electric current to drive the movement of charged particles (electrons and ions) through a conductive medium. Suffice it to say that this will almost certainly change the chemistry of a mixture. For example, assume you’ve got a mixture of some inert, insoluble solute in water. If you run a very strong electric current through water, you’ll end up decomposing the water molecules themselves into oxygen and hydrogen gases. Again, you haven’t technically separated the solute from the mixture because separation implies that you have the separated substances still around. In this example, you’ve “separated” your solute by chemically transforming your solvent into two different gases; one part of your mixture no longer exists. (Side note: electrolysis of pure water takes quite a bit of energy; on the other hand, tap water, which contains dissolved electrolytes, can be readily decomposed via electrolysis using the current delivered by a standard alkaline battery.)

As a rule of thumb, the suffix (–lysis) usually indicates chemical decomposition, and the stem that precedes the suffix usually indicates what the decomposition process involves. Examples include electrolysis (as we just discussed), hydrolysis (breaking a chemical bond using water), glycolysis (the biochemical process of breaking down glucose into smaller molecules to harness the energy released), and radiolysis (splitting a bond within atoms comprising a molecule using ionizing radiation).

Finally, as should be clear by this point, chemical reactions are not the way to go about separating mixtures. Again, the chemical substances in a mixture retain their chemical identities. Separating the constituents of a mixture essentially entails isolating these substances. Filtration can and does isolate solutes from solvents without altering their chemical identities (assuming the filter itself is chemically inert). A chemical reaction changes a substances chemical identity, and so could not properly be regarded as a method of separation, and only separation.

One way to separate the different kinds of matter in a mixture is through filtration. The correct option is A.

What is filtration?

Filtration is a physical or mechanical process by which two or more substances are of different compositions. These substances can be solid, liquid, or gas.

There are three types of filtration. These are mechanical, chemical, and biological. The different types of filtration are based on a similar principle, which is a mixture of several types poured onto a filter membrane. A specific size of the pore is present in the filter membrane.

The other options are decomposition, which is a process of breaking down substances. Electrolysis is separating charged ions and chemical reactions to form compounds.

Thus, the correct option is A. filtration.

To learn more about filtration, refer to the link:

https://brainly.com/question/14530470

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How quickly an object
accelerates is directly related
to the_____________
of the object
and the size of the___________
applied to it.

Answers

Answer:

How quickly an object  accelerates is directly related  to the Mass of the object  and the size of the Force applied to it.

Explanation:

Acceleration is directly proportional to force and inversely proportional to mass. This means that if you get pushed, the harder you are pushed, the faster you'll move (accelerate).

What is the relationship between force and acceleration?

Newton's second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration.

What is the relationship between mass and acceleration?

The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.

(100 POINTS) When thermal energy (heat) is added to a reaction, it happens _________ (faster or slower)
When thermal energy (heat) is removed from a reaction, it happens _________ (faster or slower)

Answers

Answer:

1) faster

2) slower

Explanation:

Answer:

faster

Explanation:

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple center outlined in black with two concentric black circles around the center, the inner circle having 2 small green balls on it and the outer circle having 8 small green balls on it. What experimental evidence led scientists to change from the previous model to this one? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.

Answers

Answer:

B: The colors of light emitted from heated atoms had very specific energies.

Explanation:

dont know if its the same question i had on edg but i think its B. Sorry if i didnt understand the question :)

Answer:

b

Explanation:

How does the valence electron configuration (entire last energy level configuration) relate to the group number on the Periodic Table? Use the shorthand notation in your discussion.

Answers

Answer:

The valence electron configuration determines the group to which an element belongs to.

Explanation:

The valence electron configuration of an atom of an element refers to the number of electrons in that atoms outermost shell.

The valence electron configuration is related to the group number of an element in that the number of electrons in the valence shell of an atom of an element determines the group to which an element belongs to. For example, all elements having one valence electron belong to group IA of the periodic table. Similarly, all elements having seven valence electrons belong to group VIIA of the periodic table.

This is because, since the reactivity of an element is related to its ability to either gain or lose a certain number of electrons in its valence shell, elements having same number of valence electrons have similar chemical properties.

Rainforests are located in the latitudes that have the classification A) continental. B) subarctic. C) temperate. D) tropical.

Answers

Answer:

D

Explanation:

Rainforests are tropical.

A I’m pretty sure if not text me I got you

Choose the best statement of the octet rule from those listed below atoms lose 8 electrons to become valent atoms lose 8 electrons to become valent, atoms want 8 valence electrons atoms want 8 valence electrons atoms tend to react until they have 8 valence electrons atoms tend to react until they have 8 valence electrons, atoms tend to react in order to have the s2p4 configuration atoms tend to react in order to have the s2p4 configuration, atoms tend to react in order to gain 8 valence electrons atoms tend to react in order to gain 8 valence electrons

Answers

Answer:

atoms tend to react in order to gain 8 valence electrons

Explanation:

The octet rule describes the tendency of atoms of elements to react in order to have eight electrons in their valence shell. This is because having eight valence electrons confers stability to the atoms of these elements in the compounds they form.

The octet rule only does not apply to the transition elements or the inner transition elements as only the s and p electrons are involved. the electronic configuration in atoms having an octet is s²p⁶.

For example, sodium atom has one valence electron in its valence shell but a complete octet in the inner shell; it will react with chlorine atom which has seven valence electrons to form a stable compound, sodium chloride by donating its one valence electron in order to have an octet. Similarly, the chlorine atom will then have an octet by accepting the one electron from sodium atom.

True or false

Each family represents the number of energy levels present in an atom of the element.

Answers

Answer:

true because of the elements

Using the balanced equation below,
how many grams of cesium xenon
heptafluoride would be produced
from the complete reaction of 37.8 g
cesium fluoride?

CsF + XeF6 => CsXeF7​

Answers

Answer:

Mass of CsXeF₇  = 99.3 g

Explanation:

Given data:

Mass of CsF = 37.8 g

Mass of CsXeF₇ produced = ?

Solution:

Balance chemical equation:

CsF + XeF₆   →    CsXeF₇

Number of moles of CsF:

Number of moles = mass/molar mass

Number of moles = 37.8 g/ 152 g/mol

Number of moles = 0.25 mol

Now we will compare the moles of CsF with CsXeF₇  from balance chemical equation:      

                   CsF             :         CsXeF₇

                    1                 :             1

                 0.25             :           0.25

Mass of CsXeF₇ :

Mass = number of moles × molar mass

Number of moles = 0.25 mol × 397.2 g/mol

Mass = 99.3 g

Answer:

98.84

Explanation:

1. Write chemical reaction of burning of magnesium
2. Discuss about the reactivity of magnesium
3. Discuss the nature of magnesium oxide whether it is acidic or basic.
4. What will happen?. When magnesium oxide dissolved in water and tested by red litmus.
5. When Mg burns, which type of flame is obtained.
pls answer which u can

Answers

Answer:

1.Mg+O2.......MgO2

Explanation:

2.Very reactive towards halogens and reacts with water at room temperature. 3, Magnesium oxide is a simple basic oxide. 4.It will react with water to form magnesium hydroxide which is a base turning red litmus to blue 5.should be white. hope it helped. I help people although when I post a question it is left unanswered and then gets answers after two days when I don't really need it

Which of the following statements concerning the measured number 0.3030
is correct? *
a) Only one of the zeros in the number is significant
b) Rounded off to 2 significant figures the number becomes 0.30.
c) Expressed in scientific notation the number becomes 3.03 x 10-1.
O
d) more than one correct response
e) no correct response
der below

Please explain why your answer is correct and why the others are incorrect :)

Answers

Answer:

C

Explanation:

If you move the decimal to the left it transforms the expression into scientific notation.

what is the main function of this organelle in the cell?​

Answers

Answer:

[tex]to \: use \: energy \: from \\ \: sunlight \: to \: make \: sugars.[/tex]

Explanation:

[tex]the \: main \: function \: of \: this \: organelle \\ \: in \: the \: cell \: is \: to \: use \: energy \: from \\ \: sunlight \: to \: make \: sugars.[/tex]

Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. Over time, other species are found in the disturbed areas, and the number of pioneer species decreases. Why does the number of pioneer species get less?

Answers

Answer:

The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.

Explanation:

Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. However, with time the number of pioneer species decreases.

The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.

What is the mass of 0.250 mol of chlorotrifluoromethane, CCIF3?
A. 26.1 g
B. 104 g
C. 4.78 x 10-3 g
D. 52.2g

Answers

Answer:

26.1g

Explanation:

Cclf3

=35.5

F=54/101.5

Mass=mol*mm

=0.25*1015

=26.1g

The answer would be A.26.1


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!;)

Which of the following sets of data could match the unknown element?

Answers

Answer:

✔️Metalliod, Mass: 73

Explanation:

The unknown element that is represented in the Periodic table is Germanium (Ge). It is in Group 14(IVA) and Period 4 of the periodic table. It is a metalloid and a silvery-gray substance. It's properties are intermediate between metals and nonmetals. It has a mass of 73 and an atomic number of 32.

What evidence suggests that four-legged animals came from fish?

Answers

Answer:

Paleontologists have uncovered new fossils from Tiktaalik roseae, which, while still a fish, is considered a transitional fossil that also has traits common to the first four-footed animals. This more complete picture of Tiktaalik suggests that the creature had strong, mobile hind fins.

Explanation:

hope this helps :P

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."

Describe the relationship between an element and a compound.

Answers

Answer:

An element is a material that consist of a single type of atom . each atom type contains same number of protons . chemical bonds link elements to form more complex molecules called compound A compound consist of two or more elements held together by covalent or ionic bonds.

are you clear?

what is atomic radius​

Answers

Explanation:

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definitions of atomic radius are: Van der Waals radius, ionic radius, and covalent radius

what is biogas, biomass and biodigester​

Answers

Answer:

Biogas is a type of biofuel that is naturally produced from the decomposition of organic waste. When organic matter, such as food scraps and animal waste, break down in an anaerobic environment (an environment absent of oxygen) they release a blend of gases, primarily methane and carbon dioxide.

Explanation:

Biomass is renewable organic material that comes from plants and animals. ... Biomass contains stored chemical energy from the sun. Plants produce biomass through photosynthesis. Biomass can be burned directly for heat or converted to renewable liquid and gaseous fuels through various processes.biodigester is like a mechanical stomach. It is fed with organic material, which is broken down (decomposed) by micro-organisms (bacteria) is an oxygen-free (anaerobic) environment to produce a renewable energy called biogas (methane and carbon dioxide) and other material that is mainly used as fertilizer.

Explanation:

Biogas is a type of biofuel that is naturally produced from the decomposition of organic waste.

Biomass is plant or animal material used for energy production, or in various industrial processes as raw substance for a range of products.

A Biodigester simply means a tank which digests organic material biologically. In this sense, the FilterPod is a biodigester. However, many people think of a biodigester as a tank which digests, anaerobically, without air, organic material and produces methane gas for cooking, lighting and heating ect.

which of the following is a state of matter ? particle,thermal,plasma, and diffuse ?

Answers

Answer:

a particle

Explanation:

matter takes up space, and particles take place in atoms

Answer:

plasma is a state of matter

What is force and motion

Answers

force is a strength or energy as an attribute or physical action or movement, motion is the action or process of moving or being moved

Answer:

In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes beginning moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull.

= google

lol

Which isotope has 45 neutrons?
O A. 80,36KT
OB. 80,35Br
O C. 78,345e
O D. 34,17C1

Answers

Answer:

Br.

neutron = mass number - atomic number

youcan see the answer at the pic

The isotope that has 45 neutrons is B. 80,35Br.

What is the isotope?

The neutron can be obtained by subtracting the protons from the mass number. In the question, we have a proton that is numbered, 35 and a mass number of 80.

So, to get the neutron, we would subtract the protons from the mass number as follows;

80 - 35 = 45. The element that is described by this data is Bromine. Therefore, the correct option number is B. 80,35Br.

Learn more about isotopes here:

https://brainly.com/question/14220416

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Rank the three elements according to their electronegativity,
from highest to lowest:
Fluorine (F), Silicon (Si), Chlorine (CI)

Answers

Answer:

F, Si, Cl

Explanation:

The flow of the electronegativity is up and far left. Therefore, the highest amount is in the far left and up because that is the trend. You can look up a graph on google showing the trend.

Driving automobiles and burning coal for electricity are examples of two human activities that negatively impact _______.

Answers

Answer:

I think its pollution?

In order for a gas to condense to a liquid, the attraction between its molecules _____.

Answers

Answer:

._______.

Explanation:

Explanation:

The forces of attraction between one individual molecule and another. ... Gas phase molecules will in turn condense. ... The vapor pressure of a molecular substance depends on the strength of its ... If the external pressure on a liquid is increased, the vapor pressure of the liquid must___ in order for the liquid to boil.

Which scenario is an example of primary succession?

A.
the formation of soil after a volcano


B.
the growth of weeds after a flood


C.
the establishment of a forest in an abandoned crop field


D.
the recovery of grassland after a fire

Answers

Answer:

the answer to your question is A

Which phrase best describes igneous rocks?
form when lava and magma cool

accumulate sediments following erosion

require heat and pressure to be formed

consist of many sediment layers
ctivity

Answers

Answer:

A) form when lava and magma cool

please give me brainliest :p

God bless!

Answer:

A: form when lava and magma cools

Explanation:

Got it right on Edge 2020 :)

Cone shaped mountains form as a result of which one of these events?

Answers

Answer:

Volcanic Eruptions

Explanation:

It says in the question

they are a form of volcanic eruptions
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