All categories

3 years ago

Planck’s constant is approximately equal to which of the following?

1 answer:

7 0

Henlo!
Bohr's model was unable to calculate or it required precise information about position of an electron and its velocity. It is very difficult to calculate velocity and position of an electron at the same time because electron i too small to see and may only be observed if peturbed, for example we could hit the electron with another particle such as photon or an electron, or we could apply electric or magnetic field to the electron. This will inevitably change the position of the elctron or its velocity and direction. Heisenberg aid that more precisely we can define the position of an electron, the less certainity we are able to define its velocity and vice versa.
In short, first option is correct one

You might be interested in

Ultraviolet radiation and radiation of shorter wavelengths can damage biological molecules because they carry enough energy to b

Alja [10]

Answer:

439.7nm

Explanation:

Energy of a quantum can be calculated using below formula

E=hv...........eqn(1)

But v=λ/ c .........eqn(2)

If we substitute eqn(2) into eqn(1) we have

E= hc/(λ)

Where E= energy

h= Plank's constant= 6.62607004 × 10-34 m2 kg / s

c= speed of light

c= 2.998 × 10^8 m/s

λ= wavelength= ?

But the energy was given in Kj , it must be converted to Kj/ photon for unit consistency.

Energy E= 272 kJ/mol × 1mol/6.02× 10^23

Energy= 451.83× 10^-24 Kj/ photon

E= hc/(λ)...........eqn(1)

If we make λ subject of the formula

λ= hc/E

Then substitute the values we have

λ= [(6.626 × 10^-34) × (2.998 × 10^8)]/451.83× 10^-24

λ=(0.00043965) × (1Kj/1000J) × (10^9nm/1m)

λ=439.7nm

Hence, the longest wavelength of radiation with enough energy to break carbon-sulfur bonds is 439.7nm

4 0

2 years ago

When two metals touch in the mouth, a small shock is created. this is known as<br> a?

Over [174]

<span>When two metals touch in the mouth, a small shock is created. this is known as a </span>galvanic action

7 0

3 years ago

The solubility of copper(i) chloride is 3.91 mg per 100.0 ml of solution. calculate ksp for cucl (cucl=99.00 g mol-1).

garri49 [273]

Convert Mg to grams
1g =1000mg what about 3.91 Mg
= 3.91mg x 1g/1000mg= 3.91 x10^-3 g
moles= mass/molar mass
that is 3.91 x10^-3g /99 g/mol=3.95 x10^-5moles
concentration= moles / vol in liters

that is 3.95 x10^-5/100 x1000= 3.94 x10^-4M

equation for dissociation of CUCl= CUCl----> CU^+ +Cl^-

Ksp=(CU+)(CI-)
that is (3.95 x10^-4)(3.95 x10^-4)
Ksp= 1.56 x10^-7

3 0

3 years ago

Read 2 more answers

Iron has a density of 7.87 g/cm3. What is the volume in cm3 of 3.729 g of iron?

KIM [24]

If iron has a density of 7.87g/cm³ and a mass of 3.729g, then the volume of iron is 0.474cm³

HOW TO CALCULATE VOLUME:

The volume of a substance can be calculated by dividing the mass by its density. That is;

Volume (mL) = mass (g) ÷ density (g/mL)

The density of iron is given as 7.87g/cm³ while its mass is 3.729g of iron. Hence, the volume can be calculated as follows:

Volume = 3.729 ÷ 7.87

Volume = 0.474cm³

Therefore, the volume of iron is 0.474cm³

Learn more: brainly.com/question/2040396?referrer=searchResults

6 0

2 years ago

An equimolar mixture of acetone and ethanol is fed to an evacuated vessel and allowedto come to equilibrium at 65°C and 1.00 atm

frutty [35]

The question is incomplete, the table of the question is given below

Answer:

I) xA= 0.34, yA= 0.55

ii) 76.2 mole % vapor

iii) Percentage of vapor volume = 98%

Explanation:

i) xA= 0.34, yA= 0.55

xA= 0.34, yA= 0.55

ii) 0.50 = 0.55 nv + 0.34 nL

Therefore, nV = 0.762 mol vapor and nL = 0.238 mol liquid

This shows 76.2 mole % vapor

iii) ρA= 0.791 g/cm3 and, ρE = 0.789 g/cm3

Therefore, ρ = 0.790 g/cm3

Now, we have:

MA = 58.08 g/mol and ME= 46.07 g/mol

So Ml = (0.34 x 58.08)+[(1 -0.34) x 46.07] = 50.15 g/mol

1 mol liquid = (0.762 mol vapor/0.238 mol liquid) = 3.2 mol vapor

Liquid volume = Vl= [1 mol x (50.15 g/mol)] / (0.790 g/cm3) = 63.48 cm3

Vapour volume = Vv = 3.2 mol x(22400 cm3/mol) x [(65+273)/273] = 88747 cm3

Therefore, percentage of vapour volume = 88747 / (88747+63.48) = 99.9 %

3 0

3 years ago