<u>Answer:</u> The wavelength of light is ![3.97\times 10^2nm](https://tex.z-dn.net/?f=3.97%5Ctimes%2010%5E2nm)
<u>Explanation:</u>
To calculate the wavelength of light, we use Rydberg's Equation:
![\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5Clambda%7D%3DR_H%5Cleft%28%5Cfrac%7B1%7D%7Bn_i%5E2%7D-%5Cfrac%7B1%7D%7Bn_f%5E2%7D%20%5Cright%20%29)
Where,
= Wavelength of radiation
= Rydberg's Constant = ![1.097\times 10^7m^{-1}](https://tex.z-dn.net/?f=1.097%5Ctimes%2010%5E7m%5E%7B-1%7D)
= Higher energy level = 7
= Lower energy level = 2
Putting the values in above equation, we get:
![\frac{1}{\lambda }=1.097\times 10^7m^{-1}\left(\frac{1}{2^2}-\frac{1}{7^2} \right )\\\\\lambda =\frac{1}{0.2518\times 10^7m^{-1}}=3.97\times 10^{-7}m](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5Clambda%20%7D%3D1.097%5Ctimes%2010%5E7m%5E%7B-1%7D%5Cleft%28%5Cfrac%7B1%7D%7B2%5E2%7D-%5Cfrac%7B1%7D%7B7%5E2%7D%20%5Cright%20%29%5C%5C%5C%5C%5Clambda%20%3D%5Cfrac%7B1%7D%7B0.2518%5Ctimes%2010%5E7m%5E%7B-1%7D%7D%3D3.97%5Ctimes%2010%5E%7B-7%7Dm)
Converting this into nanometers, we use the conversion factor:
![1m=10^9nm](https://tex.z-dn.net/?f=1m%3D10%5E9nm)
So, ![3.97\times 10^{-7}m\times (\frac{10^9nm}{1m})=3.97\times 10^2nm](https://tex.z-dn.net/?f=3.97%5Ctimes%2010%5E%7B-7%7Dm%5Ctimes%20%28%5Cfrac%7B10%5E9nm%7D%7B1m%7D%29%3D3.97%5Ctimes%2010%5E2nm)
Hence, the wavelength of light is ![3.97\times 10^2nm](https://tex.z-dn.net/?f=3.97%5Ctimes%2010%5E2nm)
D
A- Harvard university professor
1) Radioactive decay is the spontaneous decomposition of the unstable nucleus of an atom.
2) The emission of a particle or a photon.
For example, alpha decay is radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus).
3) The result is usually more stable element with smaller atomic number.
For example, in alpha decay atom transforms into an atom with an atomic number that is reduced by two and mass number that is reduced by four.
For example nuclear fission is radioactive decay process in which the nucleus of an atom splits into smaller parts and huge amount of energy is released.
Given :
Concentration of product [A] = 0.371 M .
Rate constant ,
.
To Find :
The rate for the reaction .
Solution :
We know , for second order reaction , rate is given by :
![r=k[A]^2\\\\r=0.761\times 0.371^2\ M/t\\\\r=0.10\ M/t](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E2%5C%5C%5C%5Cr%3D0.761%5Ctimes%200.371%5E2%5C%20M%2Ft%5C%5C%5C%5Cr%3D0.10%5C%20M%2Ft)
Therefore , the rate for the second order reaction is 0.1 M/t .
Hence , this is the required solution .
Answer:
Option A is correct = combustion
Explanation:
When substance react with oxygen combustion is occur. The substance which burned is called fuel and in this process large amount of heat is released to the surrounding. It is exothermic process.
For example:
4Li + O₂ → 2Li₂O
2Mg + O₂ → 2MgO
S + O₂ → SO₂
The product which is formed as a result of combustion reaction are called oxides.
In given examples we can see that lithium, magnesium and sulfur react with oxygen and product formed is oxides of respective elements such as lithium oxide ( Li₂O), magnesium oxide (MgO) and sulfur oxide ( SO₂ ).
Other options are incorrect because:
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AC +BD
Decomposition reaction:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B