How many moles are in 2.91 x 10^22 molecules of Helium?

Answers

Answer 1

Answer:

0.048 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{2.91 \times {10}^{22} }{6.02 \times {10}^{23} } \\ = 0.048338...[/tex]

We have the final answer as

0.048 moles

Hope this helps you


Related Questions

Which formula represents an ionic bond? 1 NaCl 2 N2O 3 HCl 4 H2O

Answers

Answer:

1 NaCl

Explanation:

NaCl is sodium chloride, and sodium chloride is an ionic compound because it's held together with ionic bonds.

A radioactive substance has a half life of 2.5 days. How much of 25.0 z is left after 10 days? ​

Answers

1.563 g

Further explanation

Given

A half life of 2.5 days ⇒ t1/2 = 2.5 days

initial sample ⇒ 25 g

duration of decay ⇒ 10 days

Required

sample left after 10 days

Analysis

Use decay Formula :

[tex]\tt Nt=No.\dfrac{1}{2}^{T/t1/2}[/tex]

Solution

[tex]\tt Nt=25.\dfrac{1}{2}^{10/2.5}\\\\Nt=25.\dfrac{1}{2}^4\\\\Nt=\boxed{\bold{1.563~g}}[/tex]

Paraphrase

Substance left after 10 days = 1.563 g

In what eon did single-celled organisms appear?

Answers

Archean is what I think but there isn’t a clear answer

A glass of fresh milk with 4% fat is an example of *
4 points
a heterogeneous mixture.
an element.
a homogeneous mixture.
a compound.

Answers

Answer:

heterogeneous

Explanation:

composition is not uniform through out

Pls someone help ASAP

Answers

Answer:

i answed it in before

Explanation:

What constitutes a solar system?

Answers

The Solar System may be divided by its components into three major regions: the inner system, the near outer system, and the far outer system. The near outer system might also be referred to as the middle system.

Our solar system consists of our star, the Sun, and everything bound to it by gravity — the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, dwarf planets such as Pluto, dozens of moons and millions of asteroids, comets and meteoroids.
Goodluck my friend!!

Why is oxygen spelt o2

Answers

Answer:

it's a diatomic molecule–which is why it is O₂.

Explanation:

Diatomic molecules are molecules composed of only two atoms, of the same or different chemical elements. Only a handful of elements on the periodic table are diatomic such as nitrogen, hydrogen, fluorine, chlorine, bromine, and iodine.

It has 2 parts of Oxygen atoms.

Which is larger potassium or bromine

Answers

Answer:

potassium.

Explanation:

located at start of period 3, will have larger radius

Answer:

bromine

Explanation:

Which one has more Thermal Energy? A cup of boiling water or a bathtub of warm water? Explain! Please answer if you can, thank you!! P.S this is science but i just put it as chemistry?

Answers

Answer:

See explanation

Explanation:

The thermal energy of a substance is affected both by its mass and by its temperature. Thermal energy is defined as the total kinetic energy of all particles in an object.

Even though the cup of water has a higher temperature, the bathtub has more thermal energy because it contains much more mass of water compared to the cup. It will release more thermal energy to the surroundings compared to the cup of boiling water.

The bathtub of warm water has a higher total thermal energy due to its bigger volume, but the cup of boiling water has a higher average kinetic energy per particle.

The thermal energy of a cup of boiling water is greater than that of a warm bathtub. The sum of all the kinetic energies of the particles in a substance is its thermal energy. The temperature of boiling water is higher than that of warm bathwater. The average kinetic energy of the particles is measured by temperature. The average kinetic energy of the particles in a cup of boiling water would be higher than that of the warm water in a bathtub, which is normally between 38 and 45 degrees Celsius (100 and 113 degrees Fahrenheit), because water has a boiling temperature of 100 degrees Celsius (212 degrees Fahrenheit).

To know more about thermal energy, here:

https://brainly.com/question/3022807

#SPJ6

The chemical formula for the ionic compound aluminum sulfite is Al2(SO3)3. Explain why there are 2 cations for every 3 anions in this compound.

Answers

my mom !!!Explanation:

Musscle man

Isomers are molecules with the same molecular formula, but different structural formulae.
How many isomers are there in C7H16?
A.6
B.7
C.8
D.9

Answers

Answer:

D 9 is the answer

Explanation:

Hope it helps you

Please mark as brainliest answer

The atoms in SBro6 are most likely being held together by what type of bond?
A. O metallic bonds
B.
ionic bonds
c. O polar covalent bonds
D
covalent bonds

Answers

Answer:

b

Explanation:im not really sure sorry if its wrong

Which is an example of potential energy?

Question 7 options:

A fox chasing a mouse


A bowling ball rolling towards the pins


A car sitting at the top of a hill


A kite flying in the air

Answers

Probably C hope this helps
C
A car sitting at the top of a hill

If you have 23mg of water, at what temperature will it Boil?

Answers

Answer:

i believe it is in the 200

Explanation:

Why does an ionic bond transfer electrons instead of sharing?

Answers

The modern definition of electronegativity is due to Linus Pauling. It is the power of an atom in a molecule to attract electrons to itself.

When the electronegativity difference between the two atoms is greater than 2.0, the bond is considered ionic; i.e. there is complete transfer (between the two atoms) of the electrons in the bond. The electronegativity (according to Pauling scale) of chlorine is 3.0, while the electronegativity of sodium is 0.9.

So, electrons are transferred because of a larger electronegativity difference.

When there is a whole transfer of valence electron between the atoms is called an ionic bond. In this type of bond construction, the atoms get contrarily charged.

The ionic bonds are formed due to electronegativity. According to Pauling, the capability of an atom to draw electrons towards itself is called electronegativity.

When there is a huge contrast in electronegativity between the atoms, the electrons are completely transferred between the atoms.

The atom that relinquishes an electron are called a cation and is positive whereas the atom that acquires an electron are called anions and are negatively charged.

Therefore, due to electronegativity, ionic bonds are formed.

To learn more about ionic bonds follow the link:

https://brainly.com/question/14484184

QUESTION 10
Which of the following is not a characteristic of ionic compounds?
A. Contains metals and non metals
B. Ions form a crystal structure
C. Conducts electricity in the solid state
D. High melting point

Answers

Answer: C. Conducts electricity in the solid state

Explanation:

Which element has a mass number of 32?

a. argon ion

b. silicon ion

C. silicon

d. sulfur

Answers

i am pretty sure it’s D.Sulfur

What Group would this element be in?

Answers

group 15 which is non metal
15
We’ll I think sorry if wrong .......

A photon has a wavelength of 299 nm. What is the frequency of this photon?
1. 1×10^16 Hz
2. 1×10^15 Hz
3. 6.65 × 10^−37 Hz
4. 6.65 × 10^−28 Hz
5. 0.00100 Hz
6. 1.98 × 10^−31 Hz
7. 8.97 × 10^10 Hz
8. 1×10^6 Hz
9. 6.65 × 10^−18 Hz

Answers

The frequency(f) of this photon : 1 x 10¹⁵ Hz

Further explanation

Radiation energy is absorbed by photons

The energy in one photon can be formulated as

[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]

Where

h = Planck's constant (6,626.10⁻³⁴ Js)

f = Frequency of electromagnetic waves

f = c / λ

c = speed of light

= 3.10⁸

λ = wavelength

A photon has a wavelength of 299 nm.

λ = 299 nm = 299 x 10⁻⁹ m = 2.99 x 10⁻⁷ m

The frequency  :

[tex]\tt f=\dfrac{3.10^8}{2.99\times 10^{-7}}\\\\f=\boxed{\bold{1\times 10^{15}~Hz}}[/tex]

MgO + HBr → MgBr2 + H2O​

Answers

Answer:

MgO + 2HBr → MgBr2 + H2O​

Explanation:

How can you increase the momentum of an object?

(a) by decreasing its velocity
(b) by increasing its friction
(c) by increasing its mass
(d) by decreasing its acceleration

Answers

Answer:

(c) by increasing it's mass

Answer:

(C) by increasing its mass

Explanation: Mass and velocity are both directly proportional to the momentum. If you increase either mass or velocity, the momentum of the object increases proportionally. If you double the mass or velocity you double the momentum.

Mass = 35g
Density = 5 g/cm3
∙What is the Volume?

Answers

Answer:

7cm3

.........

Contrast the three types of intermolecular forces.

Answers

Answer: The three major types of intermolecular interactions are dipole–dipole interactions, London dispersion forces (these two are often referred to collectively as van der Waals forces), and hydrogen bonds.

Hope this helps............ Stay safe and have a Merry Christmas!!!!!!! :D

What is the condensation point and freezing point of neon in KELVIN.

Answers

Answer:

-415.5°F (-248.6°C)

Explanation:

Answer: The melting point/condensation point of neon is 24.53888889. Of course, I'm sure you can round that. The freezing point would be 521.74. All of this is in Kelvin

2 The polar structure of water allows it to act as a solvent for many substances. Which of the
following statements best explains why water is considered polar?
F The unequal sharing of electrons results in the water molecule having a slightly negative
charge near its oxygen atoms and a slightly positive charge near its hydrogen atom.
G The equal sharing of electrons by the hydrogen and oxygen atoms form weak bonds that are
easily broken during dissociation.
H The unequal sharing of electrons results in the water molecule having a slightly positive
charge near its oxygen atoms and a slightly negative charge near its hydrogen atom.
The equal sharing of electrons by the hydrogen and oxygen atoms create a molecule that is
neutrally charged.

Answers

The answer would be F as oxygen is delta negative and hydrogen is slightly delta positive. Forming a permanent dipole.

How much electronic waste does Orlando produce ?


Answers

Answer:

20 to 50 million

Explanation:

Maggie is sitting at a table wit Fred and Florence.Maggie has 10 markers but Fred and Florence each have only 7 markers.how can they share markers so each has 8

Answers

Answer:

Give them each one so all of you is 8

Explanation:

I hope it helps:)

Fred and Florence have a combined total of 14 markers. Meaning, the amount of markers between all three is 24. If Maggie gives one marker to Fred and one marker to Florence, then each of them will have 8 markers.

Part A Read each sentence. Write the letter of the correct answer on the line.
1. Which of the following would result in a chemical change?
A boiling water
C tearing paper
B burning wood
D melting wax

Answers

Boiling water because it’s more obvious
Buring wood is the answer to that question

Similarities between sliding and fluid friction

Answers

True would be the answer

If the statement is true, select True. If it is false, select False.

In a physical change, some of the physical properties of the substance may be altered and the chemical composition remains the same.

True
False

Answers

Answer:

True

Explanation:

Yes this statement is true.

In a physical change, some of the physical properties of the substance may be altered and the chemical composition remains the same.

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