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2 years ago

What is the threshold frequency ν0 of cesium?

1 answer:

Montano1993 [528]2 years ago

4 0

I think this is what you're after:

Cs(g) → Cs^+ + e⁻ ΔHIP = 375.7 kJ mol^-1 [1]

Convert to J and divide by the Avogadro Const to give E in J per photon

E = 375700/6.022×10^23 = 6.239×10^-19 J

Plank relationship E = h×ν E in J ν = frequency (Hz s-1)

Planck constant h = 6.626×10^-34 J s

6.239×10^-19 = (6.626×10^-34)ν

ν = 9.42×10^14 s^-1 (Hz)

IP are usually given in ev Cs 3.894 eV

E = 3.894×1.60×10^-19 = 6.230×10^-19 J per photon

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The decomposition of nitryl chloride is described by the following chemical equation: 2NO2C1(g) → 2NO2 (g)-C12 (g) Suppose a two

Gnoma [55]

Answer:

Second reaction

NO2 + F -------> NO2F

Rate of reaction:

k1 [NO2] [F2]

Explanation:

NO2 + F2 -----> NO2F + F slow step1

NO2 + F -------> NO2F fast. Step 2

Since the first step is the slowest step, it is the rate determining step of the reaction

Hence:

rate = k1 [NO2] [F2]

6 0

3 years ago

Chlorine (Cl) is 76% chlorine-35 and 24% chlorine-37. Determine the average atomic mass of chlorine. Show/Explain work.

Flura [38]

Answer:

Average atomic mass of chlorine is 35.48 amu.

Explanation:

Given data:

Percent abundance of Cl-35 = 76%

Percent abundance of Cl-37 = 24%

Average atomic mass = ?

Solution:

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass = (76×35)+(24×37) /100

Average atomic mass = 2660 + 888 / 100

Average atomic mass = 3548/ 100

Average atomic mass = 35.48 amu

Average atomic mass of chlorine is 35.48 amu.

4 0

2 years ago

Conduction happens as energy flows from a warmer object to a cooler object. Which of the following is evidence of conduction?

Dmitrij [34]

Explanation:

Conduction is a form of heat transfer between one body and another. It usually occurs when a warmer object is in contact with a cooler one. Heat generally flows from a region of high temperature to a place at a lower temperature.

Conduction is very pronounced in solid bodies.
The heat transfer causes a net transfer of the average kinetic energy of one body to the other.
Some examples are: heating of iron by a hotter metallic body, the pot hand getting hotter as cooking continues, cooling of ice by touching it.

8 0

2 years ago

Select the correct value for the indicated bond angle in each of the following compounds: O-S-O angle of SO2 F-B-F angle of BF3

Stels [109]

Answer:

(A) O-S-O bond angle of SO₂ molecule = 119°

(B) F-B-F bond angle of BF₃ molecule = 120°

(D) O-C-O bond angle of CO₂ molecule = 180°

(E) F-P-F bond angle of PF₃ molecule = 96.3°

(F) H-C-H bond angle of CH₄ molecule = 109.5°

Explanation:

Bond angle refers to the angle between two adjacent chemical bonds in a molecule. The bond angle is different for different molecular geometry.

The Valence shell electron pair repulsion theory predicts the molecular geometry and shape of the given molecule by the number of lone pairs on central atom and number of atoms bonded to central atom.

(A) SO₂ molecule

The number of atoms bonded to S = 2

Number of lone pairs on S = 1

Therefore, the shape of SO₂ molecule is bent and the O-S-O bond angle is 119°.

(B) BF₃ molecule

The number of atoms bonded to B = 3

Number of lone pairs on B = 0

Therefore, the shape of BF₃ molecule is trigonal planar and the F-B-F bond angle is 120°.

(C) SCl₂ molecule

The number of atoms bonded to S = 2

Number of lone pairs on S = 2

Therefore, the shape of SCl₂ molecule is bent and the Cl-S-Cl bond angle is 103°.

(D) CO₂ molecule

The number of atoms bonded to C = 2

Number of lone pairs on C = 0

Therefore, the shape of CO₂ molecule is linear and the O-C-O bond angle is 180°.

(E) PF₃ molecule

The number of atoms bonded to P = 3

Number of lone pairs on P = 1

Therefore, the shape of PF₃ molecule is trigonal pyramidal and the F-P-F bond angle is 96.3°.

(F) CH₄ molecule

The number of atoms bonded to C = 4

Number of lone pairs on C = 0

Therefore, the shape of CH₄ molecule is tetrahedral and the H-C-H bond angle is 109.5°.

7 0

3 years ago

What would you do to change a saturated solid/liquid solution to an unsaturated solution

Semenov [28]

Explanation:

Saturated solid/liquid solution is changed to an unsaturated solution by the dilution process.

When the saturated solution is diluted by addition large quantity of solvent it changed to an unsaturated solution.

Saturated solid/liquid solution can also be changed to an unsaturated solution by increasing the temperature or heating the solution.

A saturated solution is a solution where further solute will not dissolve in the solvent.

An unsaturated solution is a solution in which has the ability to dissolve more solute.

4 0

2 years ago