Question 2 :
The number of significant figure in $6.023 \times 10 ^ { 23 } \mathrm { mole } ^ { - 1 }$ is

Question 3 :
An outstanding book on the wave nature of light titled "An Introduction to the Study of Wave Mechanics" was published in $1930$. Who was its author?

Question 4 :
In scattering experiment, find the distance of closest approach, if a $6$MeV $\alpha$-particle is used.

Question 6 :
What is the wavelength of the most energetic photon emitted in the Balmer's series of the hydrogen atom?

Question 7 :
If an element has 22 electrons then what will be its atomic number?

Question 8 :
In the geiger-marsden experiment what percentage of the $\alpha$ particles were deflected by an angle more than $1^o$.

Question 17 :
Nuclear fission experiments show that the neutrons split the uranium nuclei into two fragments of about same size. This process is accompanised by the emission of several

Question 20 :
Which of the following has the mass closest in value to that of the positron <br> ( <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e901a2a75509d0792b37132"> )

Question 23 :
The splitting of line into groups under the effect of magnetic field is called

Question 24 :
In Bohr model of the hydrogen atom, the lowest orbit corresponds to

Question 25 :
<img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e9019bb75509d0792b37099">  has half-life 5700 year. At the end of 11400 years, the actual amount left is

Question 26 :
When a beam of white light is passed through sodium vapours and then through a spectrometer, spectrum so obtained has two dark lines present in the yellow region. This spectrum is called

Question 27 :
The spectra used to identify the elements in&#160;the mixture is :<br/>

Question 28 :
An element has number of electrons &#160;= 2. Then what will be its atomic number?.

Question 29 :
Smallest particle in a chemical element or compound that has the chemical properties of that element or compound is

Question 31 :
In nuclear fission, the fission reactions proceeds with a projectile. Which of the following suits the best

Question 33 :
Nucleus of an atom whose atomic mass is 24 consists of

Question 36 :
A nucleus is bombarded with a high speed neutron so that resulting nucleus is a radioactive one. This phenomenon is called

Question 38 :
If the mass of a radioactive sample is doubled, the activity of the sample and the disintegration constant of the sample are respectively

Question 40 :
The proper life of pion ( <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e9018ad75509d0792b36f1f"> ) is <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e9019f653fc1406d1d68199"> . In a beam of pions travelling with a speed of 0.9 c, the pion, in the laboratory frame, can travel a maximum distance of

Question 41 :
The average value of output direct current in a full wave rectifier is

Question 42 :
An electron jumps from $6^{th}$ shell in an hydrogen atom, the number of Lyman emission lines will be:

Question 43 :
In half life of a radio isotope is 2 seconds and number of atoms are only 4, then after one half life remaining (without decay) atoms are probably

Question 45 :
When a slow neutron goes sufficiently close to a <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e90173053fc1406d1d67d91">  nucleus, then the process that takes place is

Question 46 :
If half-life of a radioactive atom is <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e901a8c53fc1406d1d68261"> , then its decay constant would be

Question 48 :
If an element X has mass number and number of proton 8 then identify element X