28 grams of H2 are produced from an experiment. How much volume would they displace at STP?

Answer:

A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs.

Compounds used as medicines are most often organic compounds, which are often divided into the broad classes of small organic molecules (e.g., atorvastatin, fluticasone, clopidogrel) and "biologics" (infliximab, erythropoietin, insulin glargine), the latter of which are most often medicinal preparations of proteins

Explanation:

Answer:

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

N = 3.1 × 10²² molecules of H2O

We have

[tex]n = \frac{3.1 \times {10}^{22} }{6.02 \times {10}^{23} } \\ = 0.05149501...[/tex]

We have the final answer as

Hope this helps you

Thank you for the answer, it is much appreciated, and if you haven't seen it already, it is B.

Answer:

The answer is B on edge

Explanation:

Answer:

it rusts when exposed to air

Answer:

A

Explanation:

Answer: E= 4.085 x 10^-19 J ; Wavelength= 4.862 x 10^-7 m

Explanation:

Sorry for the messy work, but I hope this helps.

Remember:

Plancks constant (h)=  6.626x10^-34 Js

Speed of light (c) = 2.998 x 10^8 ms^-1

What I did:

I found the energy first with the given frequency. Don't forget to convert your units to s^-1! They are actually the same, you dont need to do math for that conversion, just a simple Hz to s^-1.

For the wavelength, I multiplied plancks constant (h) and speed of light (c) together. With that number I divided by the energy found which 4.085 x 10^-19J. Also, be sure to cross off the units because it can get very confusing.  

The energy of the photon is 4.08 x 10⁻¹⁹ J

The wavelength of the photon is 2.58 x 10⁻⁶ m

The given parameters;

frequency of the photon, f = 6.165 x 10¹⁴ Hz

The energy of the photon is calculated as;

E = hf

where;

h is Planck's constant = 6.626 x 10⁻³⁴ Js

E = (6.626 x 10⁻³⁴)( 6.165 x 10¹⁴)

E = 4.08 x 10⁻¹⁹ J

The wavelength of the photon is calculated as;

v = fλ

where;

v is the speed of light = 3 x 10⁸ m/s

[tex]\lambda = \frac{v}{f} \\\\\lambda = \frac{3\times 10^8}{1.165\times 10^{14}} \\\\\lambda = 2.58 \times 10^{-6} \ m[/tex]

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Answer:

5 atoms

Explanation:

there is 1 carbon atom and 4 hydrogen atoms

Answer:

White whale

Explanation:

Just because I never seen a white whale:)

Answer:

What are the Answer choices

Answer:

A. Diffusion

Explanation:

A.Diffusion  - this is correct. Diffusion is the process where small molecules enter the cell by moving from a high concentration to a low concentration through a semi-permeable membrane.

B.Exocytosis  - this is incorrect. Exocytosis is a cell transport mechanism where the cell uses a system of vesicles to transport cargo outside of the cell. The vesicles fuse to the cell membrane and deliver the cargo outside.

C.Osmosis  - this is incorrect, osmosis is a type of diffusion specific to water molecules

D.Endocytosis - this is incorrect. Endoocytosis is a cell transport mechanism where the cell uses a system of vesicles to transport cargo into the cell. The cell membrane engulfs the molecules and brings them into the cell via the vesicle

Answer:

7

⋅

g

⋅

c

m

−

3

Explanation:

Answer:

This process is considered as a cycle because it continues and dosent stops. This process includes the evaporation of watet from earth surface due to heat.this water is converted in to water vapours. After reaching clouds it condences back. When the clouds become heavy with watef it falls back on earth as rain.and the process repeats.

Explanation:

Answer:

Answer Option A) To attain a noble-gas electron configuration.

Explanation:

Correct answer from test

Taking into account the definition of covalent bond and octet rule, the correct answer is option A.  Atoms share electrons in covalent bonds to achieve a noble gas electron configuration.

The covalent bond is the chemical bond that occurs between atoms of non-metallic elements. These atoms have many electrons at their outermost level and have a tendency to share them to acquire the stability of the noble gas electronic structure. In this way a molecule is formed.

The tendency of the elements to reach a stable configuration is known as the octet rule. For this, the octet rule explains that there must be eight electrons in their last energy levels, thus acquiring the structure of a noble gas.

So, a covalent bond is a force that joins two atoms of non-metallic elements to form a molecule in order to comply with the octet rule.

Finally, the correct answer is option A.  Atoms share electrons in covalent bonds to achieve a noble gas electron configuration.

Learn more:

Answer:

Yes

Explanation:

Im not sure about the question but potassium fluoride, KF is an ionic compound.

Answer:

4+3=3+3+2

Explanation:

4Ni(oh)3+3pb(so4)2=3pb(oh)4+2Ni2(so4)3

The outmost free electron which is present in the outer shell is called valency. The number of elements joining together to form the compound also depends on the valency.

Each electron has revolved around the nucleus and that path is considered as orbit. The orbit is as follows:-

The free electrons are usually lie in the outmost shell.

Hence according to the question, the correct option is S and P orbit.

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Answer:

a) 7.14e19 Hz

b) 2.298e-27 J

c) 2.793e-19 J; 7.117e9 nm

d) 7.5e14 Hz; 4.96e-19 J

e) 6.2947e-18 J; 31.6 nm

f) 2.21e-22 J

g) 7.1e-19 J; 1.1e15 Hz

h) 3.422e-19 J; 581 nm

i) 4.2e14 Hz

j) 1.92e8 m

k) 7.14e16 Hz; Ultraviolet

Explanation:

Frequency: ν       Wavelength: λ       Energy: E       Speed of light: C (3.00e8)       Planck's Constant: h (6.626e-34)

ν -> λ    λ = C/ν

λ -> ν    ν = C/λ

For either of these equations, wavelength must be converted to meters or nanometers, depending on the equation.

For ν -> λ, after doing the equation, convert the wavelength into nanometers by dividing by 1e-9.

For converting λ -> ν, convert the wavelength into meters by multiplying by 1e-9.

For energy: E = hν = hc/λ

Now that the setup is out of the way:

a) Violet light has a wavelength of 4.20 x 10-12 m. What is the frequency?

λ -> ν    ν = C/λ

[tex]\frac{3.00e8}{4.20e-12}[/tex] = 7.14e19 Hz

b) A photon has a frequency (n) of 3.468 x 106 Hz. Calculate its energy

E = hν = hc/λ

(6.626e-34) (3.468e6) = 2.298e-27 J

c) Calculate the energy (E) and wavelength (l) of a photon of light with a frequency of 4.215 x 1014 Hz.

E = hν = hc/λ

(6.626e-34) (4.215e14) = 2.793e-19 J

ν -> λ    λ = C/ν

[tex]\frac{3.00e8}{4.215e14}[/tex] = 7.117 m

[tex]\frac{7.117m}{1}*\frac{1nm}{1e-9m}[/tex] = 7.117e9 nm

d) Calculate the frequency and the energy of blue light that has a wavelength of 400 nm  (h = 6.62 x 10-34 J-s).

λ -> ν    ν = C/λ

[tex]\frac{400 nm}{1} *\frac{1e-9m}{1nm}[/tex] = 4e-7 m

[tex]\frac{3.00e8}{4e-7}[/tex] = 7.5e14 Hz

E = hν = hc/λ

(6.626e-34) (7.5e14) = 4.96e-19 J

e) Calculate the wavelength and energy of light that has a frequency of 9.5 x 1015 Hz.

ν -> λ    λ = C/ν

[tex]\frac{3.00e8}{9.5e15}[/tex] = 3.16e-8 m

[tex]\frac{3.16e-8m}{1}*\frac{1nm}{1e-9m}[/tex] = 31.6 nm

E = hν = hc/λ

(6.626e-34) (9.5e15) = 6.2947e-18 J

f) A photon of light has a wavelength of 0.090 cm. Calculate its energy.

E = hν = hc/λ

Convert the wavelength from cm to meters:

[tex]\frac{0.090cm}{1} *\frac{1m}{100cm}[/tex] = 9e-4 m

[tex]\frac{(6.626e-34)(3.00e8)}{9e-4}[/tex] = 2.21e-22 J

g) Calculate the energy and frequency of red light having a wavelength of 2.80 x 10-5 cm.

E = hν = hc/λ

Convert the wavelength from cm to meters:

[tex]\frac{2.80e-5cm}{1} *\frac{1m}{100cm}[/tex] = 2.8e-7 m

[tex]\frac{(6.626e-34)(3.00e8)}{2.8e-7}[/tex] = 7.1e-19 J

λ -> ν    ν = C/λ

Convert the wavelength from cm to meters:

[tex]\frac{2.80e-5cm}{1} *\frac{1m}{100cm}[/tex] = 2.8e-7 m

[tex]\frac{3.00e8}{2.8e-7}[/tex] = 1.1e15 Hz

h) Calculate the energy (E) and wavelength (l) of a photon of light with a frequency of 5.165 x 1014 Hz.

E = hν = hc/λ

(6.626e-34) (5.165e14) = 3.422e-19 J

ν -> λ    λ = C/ν

[tex]\frac{3.00e8}{5.165e14}[/tex] = 5.81e-7 m

[tex]\frac{5.81e-7m}{1}*\frac{1nm}{1e-9m}[/tex] = 581 nm

i) The wavelength of green light from a traffic signal is centered at 7.20 x 10-5 cm. Calculate the frequency.

λ -> ν    ν = C/λ

Convert the wavelength from cm to meters:

[tex]\frac{7.20e-5 cm}{1} *\frac{1m}{100cm}[/tex] = 7.2e-7 m

[tex]\frac{3.00e8}{7.2e-7}[/tex] = 4.2e14 Hz

j) If it takes 1.56 seconds for radio waves (which travel at the speed of light) to reach the moon from Earth, how far away is the moon?

  All we want to do here is to convert frequency (speed) to wavelength (distance). This problem requires a bit of thought, but it isn't bad once you realize that frquency is speed and wavelength is distance. It becomes just like the other problems after that. Also, I'll leave this distance in meters, but I think you can figure out how to convert it if it wants it in another unit.

  One second is equal to 1 Hertz, so our frequency is 1.56 Hz.

ν -> λ    λ = C/ν

[tex]\frac{3.00e8}{1.56}[/tex] = 1.92e8 m

  The actual distance from the earth to the moon via google is 3.84e7, but sometimes problems like this will mess with the numbers to make sure that you didn't just look up the answer. I'm still pretty sure that this is right, however.

k) Calculate the frequency of light that has a wavelength of 4.20 x 10-9m. Identify the type of electromagnetic radiation.

First, we convert wavelength to frequency, as normal:

λ -> ν    ν = C/λ

[tex]\frac{3.00e8}{4.20e-9}[/tex] = 7.14e16 Hz

Then we identify the electromagnetic wave type. You can look up a conversion chart for these on google, but since our frequency is in the e15 - e17 range, this light is considered ultraviolet.

Answer:

The density of object is 0.52 g/cm³

Explanation:

Given data:

Density of object = ?

Mass of object = 13 g

Volume of object = 25 cm³

Solution:

Formula:

d = m/v

d = 13 g/ 25 cm³

d = 0.52 g/cm³

Thus, the density of object is 0.52 g/cm³.

Answer:

The answer is d

Explanation:

Answer:

-are usually single celled

-do not contain membrane-bound organelles

-have DNA located in cytoplasm

Explanation:

currently taking the test

Answer:

Wavelength refers to the length of a wave from one peak to the next. The amplitude or height of a wave is measured from the peak to the trough. The wavelength is measured from peak to peak. Wavelength is directly related to the frequency of a given wave form.

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.

Answer:

c tarnishes in air

Explanation:

After silver has been exposed to air that contains sulphur gases, discoloration would occur. there would be darkening that is caused by the reaction with gases.When any silver object tarnishes, it brings about a disfiguring of that object. Hydrogen sulphide would be needed for this to happen. silver sulphide is black and a if a thin layer should form on any surface, it ill darken it. This  is what we refer to as tarnishing.

Answer:

c

Explanation:

it tarnishes in air

Answer

A

Explanation

letter a kase tama

Answer:

Tea is getting hot on the stove.  

2) As the tea and water gets hot, some combined molecules of tea and water will escape from the teapot.  

3) Those escaped molecules now have the entire free space of the entire room to float around in, which they do (because they have high kinetic energy due to being heated).  

4) Hence, in this scenario, your nose will detect a few of those molecules and you smell hot or warm tea.  

5) Cold tea would be a different story. Cold beverages like cold tea do not have the kinetic energy where molecules can 'break free' of the surrounding container. Someone could be sitting in the room having a can or bottle of cold tea and you would not notice that when you walked in the door.

Answer:

b. impulse decision

Explanation:

In this scenario, Reggie suddenly decided to drive to the Grand Canyon, because he had never seen it. He didn't even have a map showing him how to get there! Reggie made an impulse decision.

An impulse decision can be defined as a type of decision an individual makes without having a clear thought about the decision. Thus, an impulsive decision is strictly based on an individual's inclination, instinct, whim or sudden desire to do something.

This ultimately implies that, decisions that are made spontaneously without due diligence and considerations refer to an impulse decision.

Hence, Reginald's decision is an impulse decision because he suddenly decided to drive to go see a place (Grand Canyon) he hasn't seen before, even though he had no map to use as a guide or direction.

Answer:    b

Explanation:

Answer:

if their genes want to grow any more, they'll grow.

Explanation:

Answer:

its 2 on ed I promise do not listen to the brainiest

Explanation:

Answer:

B)2

Explanation:

Answer:

b

Explanation: