Structure of At...

Energy of the third orbit of Bohr's atom is:

Which element with lowest atomic number .

What is the ratio of time periods $$(\dfrac{T_1}{T_2})$$ in $$2^{nd}$$ orbit of hydrogen atom to third orbit of $$He^+$$ ion?

The carbonate of a metal is isomorphous (similar formula) with magnesium carbonate and contains 6.091 percent of carbon. The atomic weight of metal is:

A single electron orbits a stationary nucleus of charge $$+Z$$, where $$Z$$ is a constant. It requires 47.2 eV to excite electron from second Bohr orbit to third Bohr orbit, find the value of $$Z$$.

Multiple of fine structure of spectral lines is due to:

If the speed of electrons in Bohr's first obtain of hydrogen is $$'X'$$ the speed of electrons in third orbit is:

What happens to the atomic number during a chemical reaction?

Which of the following parameters are not same for all hydrogen like atoms and ions in their state?

Boron has 2 stable isotopes, $$10-B$$$$(19$$%) and $$11-B$$($$81$$%) the atomic mass that should appear for boron in the periodic table is: