Structure of At...

Mass numbers of Li, Be and B are 7, 9 and 10 respectively. Which of the following has two electrons, three protons and four neutrons?

The ratio of the energy of the electron in the ground state of hydrogen to the electron in first excited state of $$Be^{3+}$$ is 

The Bohr radius of the fifth electron of phosphorus (atomic number = 15) acting as dopant in silicon (relative dielectric constant = 12) is 

According to Bohr's theory radius of $$n^{th}$$ shell is given as $$\dfrac {1}{r_{n}}\propto Z^{y}$$ ($$Z$$ is atomic number). Here $$'y'$$ is:

The radius of the orbit of an electron in a Hydrogen-like atom is $$3{ a }_{ 0 }$$, where $${ a }_{ 0 }$$ is the Bohr radius. Its orbital angular momentum is $$\frac { 3h }{ 2\pi  } $$. It is given that h is Planck's constant and R is Rydberg constant. The possible wavelength, when the atom de-excites is :

$$M^{3+}$$ (mass number $$56$$) contains $$30.4\%$$ more neutrons than electrons. Thus, atomic number of the ion is.

Which one of the following is considered as the main postulate of Bohr's model of atom

Any $$nf-$$ orbital can accommodate upto:-

Which one of the following species will give  a series of spectral lines similar to that of $$Mg^{2+}$$?

If the Aufbau principle had not been followed, $$Ca(Z=20)$$ would have been placed in the?