Structure of Atom Test - 11

The spectral lines which arise due to transition of electrons from higher energy levels to the second energy level will appear in visible region. Balmer series lie in the visible region of EM spectrum.

Neils Bohr proposed a model of hydrogen atom based on the quantum theory and explained the atomic spectrum of hydrogen.

The uncertainty principle says that we cannot measure the position (x) and the momentum (p) of a particle with absolute precision. The more accurately we know one of these values, the less accurately we know the other. Multiplying together the errors in the measurements of these values (the errors are represented by the triangle symbol in front of each property, the Greek letter "delta") has to give a number greater than or equal to half of a constant called "h-bar". This is equal to Planck's constant (usually written as h) divided by 2π.

Δx. Δp ≥  h/4π

For n=4 the possible  values of l are  0,1, 2, 3. The orbital with l = 3 is f orbital

Energy of orbital is determined by the n+l value. The orbital having higher n+l value will have higher energy. If n+l value is same then orbital having higher n value will have higher energy.

Kr has atomic no. 36. And in Kr total number of d-electrons is equal to the difference between the numbers of total p and total s electrons.

no. of d electrons is 10

no of p electrons- no of s electrons= 18-8= 10

In the formation of a cation with 3⁺ charges the atom looses 3 elctrons.  

The no of electrons in the atom will be 18 + 3 = 21.

 In a neutral atom the no.of protons is equal to the no. of electrons. So atomic no. is 21.

An electron is shielded from the attractive interactions of the nucleus by the electrons in the inner shells.The repulsive and attractive  interactions of an electron depend on the shell and the orbital in which the electron is present