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
RSB [31]
3 years ago
15

What is the kinetic energy of the emitted electrons when cesium is exposed to UV rays of frequency 1.3×1015Hz?

Chemistry
2 answers:
-BARSIC- [3]3 years ago
8 0

The kinetic energy of the emitted electrons of cesium when it is exposed to UV rays of frequency 1.3\times{10^{15}}\;{\text{Hz}} is \boxed{8.614\times10^{-19}\text{ J}}.

Further Explanation:

Photoelectric effect:

When light is made to fall on any substance, electrons are emitted from it. This is known as the photoelectric effect and the emitted electrons are called photoelectrons. The electrons are emitted because of the transference of energy from light to the electrons.

Cesium is a member of the alkali metal group so it is highly reactive and shows the photoelectric effect to the maximum extent. It can remove its electron so easily because of its atomic size. Due to the large atomic size of cesium, its outermost electrons are held very less tightly to the nucleus and therefore removed easily.

According to the Planck-Einstein equation, the energy is proportional to the frequency and is expressed as follows:

{\text{E}}={\text{hv}}                                    …… (1)

Here,

{\text{E}} is the energy.

h is the Plank’s constant.

\nu is the frequency.

The frequency of UV rays 1.3\times{10^{15}}\;{\text{Hz}}is or 1.3\times{10^{15}}\;{{\text{s}}^{-1}}

The value of Planck’s constant is 6.626\times{10^{-34}}\;{\text{J}}\cdot{\text{s}}.

Substitute these values in equation (1)

\begin{gathered}{\text{E}}=\left({6.626\times{{10}^{-34}}\;{\text{J}}\cdot{\text{s}}}\right)\left({1.3\times{{10}^{15}}\;{{\text{s}}^{-1}}}\right)\\= 8.614\times{10^{-19}}\;{\text{J}}\\\end{gathered}

But when electrons are ejected out from the surface of the substance, all of its energy is considered as kinetic energy.

So the kinetic energy of the electrons is {\mathbf{8}}{\mathbf{.614\times1}}{{\mathbf{0}}^{{\mathbf{-19}}}}\;{\mathbf{J}}

Learn more:

1. Calculate the frequency of n = 6 in the Lyman series: brainly.com/question/5762197

2. The energy of a photon in light: brainly.com/question/7590814

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Structure of the atom

Keywords: kinetic energy, frequency, energy, photoelectric effect, Planck's constant, light, electrons, photoelectrons, proportional, transference, reactive, cesium.

Sonja [21]3 years ago
6 0

Answer:

We know that

ħf = ф + Ekmax  

where  

ħ = planks constant = 6.626x10^-34 J s  

f = frequency of incident light = 1.3x10^15 /s (1 Hz =

1/s)

ф = work function of the cesium = 2.14 eV  

Ekmax = max  kinetic energy of the emmitted electron.  

We distinguish that:

1 eV = 1.602x10^-19 J

So:

2.14 eV x (1.602x10^-19 J / 1 eV) = 3.428x10^-19 J

So,

Ekmax = (6.626x10^-34 J s) x (1.3x10^15 / s) - 3.428x10^-19 J

= 8.6138x10^-19 J - 3.428x10^-19 J = 5.1858x10^-19 J  

Answer:

5.19x10^-19 J  

Kinetic energy:

In physics, the kinetic energy of an object is the energy that it owns due to its motion. It is defined as the work required accelerating a body of a given mass from rest to its specified velocity. Having expanded this energy during its acceleration, the body upholds this kinetic energy lest its speed changes.

Answer details:

Subject: Chemistry

Level: College

Keywords:

• Energy  

• Kinetic energy

• Kinetic energy of emitted electrons

Learn more to evaluate:

brainly.com/question/4997492

brainly.com/question/4010464

brainly.com/question/1754173

You might be interested in
CNC NaCl HCL are all classified as
Leona [35]
<span>A) elements and compounds. Compounds are two combined elements.</span>
6 0
2 years ago
Why are some examples of a chemical reaction not actually foolproof evidence that of a chemical reaction?13, 8th grade, and I'm
kvasek [131]
So basically, the change in color effects the amount of cations in the solution making it a physical change rather than a chemical one, defying the law of conservation of mass! I hope this helped! (The only time the change in color affects the amount of cations is in the Alkaline Earth Metals)

source: college science teacher 
7 0
3 years ago
CaC2(s) + 2H2O(l) --&gt; Ca(OH)2(aq) + C2H2(g) In the reaction above, 0.5487 grams of calcium carbide are completely consumed to
jasenka [17]

Answer:

239.7mL

Explanation:

Using the general gas equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas constant (0.0821 Latm/molK)

T = temperature (K)

The balanced chemical equation in this question is as follows:

CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g)

From the equation, 1 mole of CaC2 produces 1 mole of ethylene gas, C2H2.

Using mole = mass/molar mass

Molar mass of CaC2 = 40 + 12(2)

= 40 + 24

= 64g/mol

mole = 0.5487/64

mole = 0.00857mol of CaC2

Hence, 0.00857mol of CaC2 produced 0.00857mol of C2H2

Based on the information provided, n = 0.00857mol, T = 43°C = 43 + 273 = 316K, p = 0.926 atm

PV = nRT

V = nRT/P

V = 0.00857 × 0.0821 × 316/0.926

V = 0.222/0.926

V = 0.2397L

In mL, volume = 0.2397 × 1000

= 239.7mL

3 0
3 years ago
How many lead atoms are in a cube of lead that has a volume of 2.18 cm3 if the density of lead is 11.3 g/cm3?
Anit [1.1K]
10000000.................
3 0
3 years ago
Which action does the executive branch take as part of the government spending process? A.Executive branch agencies meet with Co
12345 [234]
The correct answer is C. Executive branch agencies plan their fiscal budgets for the year. (Apex)
7 0
3 years ago
Read 2 more answers
Other questions:
  • A liquid is considered an acid if it has a lot of
    8·1 answer
  • When backpacking in the wilderness, hikers often boil water to sterilize it for drinking. Suppose that you are planning a backpa
    6·1 answer
  • Is the lithosphere a solid rock or a liquid rock
    15·1 answer
  • In a 4.00 L pressure cooker, water is brought to a boil. If the final temperature is 115 °C at 3.10 atm, how many moles of steam
    10·1 answer
  • Describe two tests that you can run to determine if something is a substance or a mixture.
    11·1 answer
  • What is the difference between an anion and a cation
    9·1 answer
  • John Dalton believed which of the following about atoms?
    12·1 answer
  • What gas is produced when calcium metal is dropped in water
    6·1 answer
  • Can dowels be chopsticks, since both of them are wood?
    8·2 answers
  • Please help people! science science! thank you!
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!