If an element emits photon in its ground state due to electronic transition,then its atomic no. decreases,WHY???

I had asked here that y does atomic no. DECREASE????But i didn't get the relevant answer.

The de-broglie wavelenght of an electron accelerated by an electric field of V volts is 1.23/V nm,i need its solution???

HERE,I'm not getting 1.23 after the tedious calculations.CAn u help me out a shortcut method?

Dear student,

When an electron absorbs or emits a photon (light), it makes a transition between the orbital energy levels. The energy of the electron will be equal to the difference of energies between the two levels. Electrons are said to be at ground state when the electrons in an atom are at their least  possible energy level and electrons tend to be at an excited state when they are at a higher energy levels. On absorbing light, an electron can get excited to move to higher energy levels. Similarly, an excited electron can move to lower energy levels when it emits light. By analyzing the spectrum of the emitted and absorbed photons, data on the energy levels and structures of electrons can be obtained since the photon's frequency is proportional to its energy.

Please feel free to ask your queries here. We are all IITians and here to help you in your IIT JEE preparation.

All the best.

Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively : Click here to download the toolbar..

Askiitians Expert

Sagar Singh

B.Tech, IIT Delhi

Approved

dear arshiya,

 It has to do with the electrons and the orbitals. As you add electrons and protons across a period, the electronegativity (electron pull) increase, and in turn causes the atomic radius to decrease. But, when you go down a group, the size increases because of the added electron orbital sub-shell being added. when those orbitals get filled with more electrons, they get smaller

Don’t forget to approve the answer if it is beneficial to you… !!

We are all IITians and here to help you in your IIT JEE preparation.

Now you can win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar : Click here to download the toolbar.. 

AMAN BANSAL