1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Bond [772]
3 years ago
13

(A) Calculate the wavelength (in nm) of light with energy 1.89 × 10–20 J per photon, (b) For light of wavelength 410 nm, calcula

te the number of photons per joule, (c) Determine the binding energy (in eV) of a metal if the kinetic energy possessed by an ejected electron [using one of the photons in part (b)] is 2.93 × 10–19 J.
Chemistry
1 answer:
ad-work [718]3 years ago
7 0

<u>Answer:</u>

<u>For A:</u> The wavelength of the light is 1.052\times 10^4nm

<u>For B:</u> The number of photons per joule is 2.063\times 10^{18}

<u>For C:</u> The binding energy of a metal is 1.197 eV.

<u>Explanation:</u>

The equation used to calculate the energy of a photon follows:

E=\frac{hc}{\lambda}            ......(1)

where,

E = energy of a photon

h = Planck's constant = 6.626\times 10^{-34}J.s

c = speed of light = 3\times 10^{8}m/s

\lambda = wavelength

  • <u>For A:</u>

Given values:

E = 1.89\times 10^{-20}J

Putting values in equation 1, we get:

\lambda=\frac{(6.626\times 10^{-34}J.s)\times (3\times 10^8m/s)}{1.89\times 10^{-20}J}\\\\\lambda=1.052\times 10^{-5}m

Converting the wavelength into nanometers, the conversion factor used is:

1m=10^9nm

So, \lambda=1.052\times 10^{-5}m\times \frac{10^9nm}{1m}=1.052\times 10^4nm

Hence, the wavelength of the light is 1.052\times 10^4nm

  • <u>For B:</u>

Given values:

\lambda=410nm=410\times 10^{-9}m

Putting values in equation 1, we get:

E=\frac{(6.626\times 10^{-34}J.s)\times (3\times 10^8m/s)}{410\times 10^{-9}m}\\\\E=4.848\times 10^{-19}J

To calculate the number of photons, we use the equation:

\text{Number of photons}=\frac{\text{Total energy}}{\text{Energy of a photon}}

Total energy = 1 J

Energy of a photon = 4.848\times 10^{-19}J

Putting values in the above equation:

\text{Number of photons}=\frac{1J}{4.848\times 10^{-19}J}\\\\\text{Number of photons}=2.063\times 10^{18}

Hence, the number of photons per joule is 2.063\times 10^{18}

  • <u>For C:</u>

To calculate the binding energy of a metal, we use the equation:

E=K+B             .....(2)

E = Total energy

K = Kinetic energy of a photon

B = Binding energy of metal

Converting the energy from joules to eV, the conversion factor used is:

1eV=1.602\times 10^{-19}J

Using the above conversion factor:

K=2.93\times 10^{-19}J=1.829eV\\\\E=4.848\times 10^{-19}J=3.026eV

Putting values in equation 2:

B=(3.026-1.829)eV=1.197eV

Hence, the binding energy of a metal is 1.197 eV.

You might be interested in
Mary put a plant on a table in her room. After a few weeks, she saw that the stem of the plant was starting to bend toward the w
alexandr402 [8]
 a. the need for light
6 0
3 years ago
An element with the smallest anionic (negative-ionic) radius would be found on the periodic table in
Advocard [28]
The correct answer for, An element with the smallest anionic (negative-ionic) radius would be found on the periodic table in, is <span>Group 17, Period 2.</span>
5 0
3 years ago
A student ran the following reaction in the laboratory at 671 K: 2NH3(g) N2(g) + 3H2(g) When she introduced 7.33×10-2 moles of N
vaieri [72.5K]

Answer:

Kc = 8.05x10⁻³

Explanation:

This is the equilibrium:

                 2NH₃(g)   ⇄     N₂(g)     +     3H₂(g)

Initially       0.0733

React         0.0733α          α/2                3/2α

Eq     0.0733 - 0.0733α    α/2                0.103

We introduced 0.0733 moles of ammonia, initially. So in the reaction "α" amount react, as the ratio is 2:1, and 2:3, we can know the moles that formed products.

Now we were told that in equilibrum we have a [H₂] of 0.103, so this data can help us to calculate α.

3/2α = 0.103

α = 0.103 . 2/3 ⇒ 0.0686

So, concentration in equilibrium are

NH₃ = 0.0733 - 0.0733 . 0.0686 = 0.0682

N₂ = 0.0686/2 = 0.0343

So this moles, are in a volume of 1L, so they are molar concentrations.

Let's make Kc expression:

Kc= [N₂] . [H₂]³ / [NH₃]²

Kc = 0.0343 . 0.103³ / 0.0682² = 8.05x10⁻³

3 0
3 years ago
Manual says that he has reduce the amount of thermal energy in a cup of hot chocolate without lowering the temperature.How is th
ANEK [815]
Friction. It transforms other forms of energy into thermal energy
7 0
3 years ago
When Mendeleev started his work on organizing the elements, about how many had
Talja [164]

Answer:

About 60.

Explanation:

Mendeleev knew of 63 elements. He wrote their properties on cards and arranged them in order of atomic mass.

That's how he discovered that the properties of elements are periodic functions of their atomic masses.

8 0
3 years ago
Other questions:
  • Which subatomic particle can change the molecular geometry of a molecule?
    10·1 answer
  • How marly electrons are in an atom of elemental<br> sodium?
    15·2 answers
  • Thermal radiation emitted by objects allows us to feel infrared<br> energy as _____
    7·1 answer
  • How would an apple, potato, and onion all taste the same?
    9·1 answer
  • I'll give brainiest a person who answers first correctly :) I promise
    7·2 answers
  • Nick needs 3.5 moles of sodium fluoride (NaF) for a solution he is mixing in the lab. How many grams of NaF does Nick need to me
    13·1 answer
  • -HELP-<br>How many molecules are contained in 125 grams of oxygen gas (O2)?
    7·1 answer
  • Which of the following is not a trend that varies systematically in the periodic table
    13·2 answers
  • Which one is the molecule?<br><br> Oxygen (O)<br><br> Dioxygen (O2)
    12·2 answers
  • Complete and balance the following:(c) FeS(s) + HCl (aq) →
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!