Question

The radius of $1^{st}$ Bohr orbit in H-atom is $0.537\mathring{A}$, then radius of $3^{rd}$ Bohr orbit is______

• A. $4.833\mathring{A}$
• B. $0.0596\mathring{A}$
• C. $1.611\mathring{A}$
• D. $0.1790\mathring{A}$

Answer 1

The correct option is A $4.833\mathring{A}$

There is a formula in chemistry regarding the Bohr's radius of hydrogen atom $r=r^{0}n\times n÷z$

In this formula $R$ is the radius and $n$ is the radius in which the electron is lying $z$ is the atomic number of the atom in the case of hydrogen atom $2$ is equal to one $r^0=0.537$

Therefore the Bohr's radius of third orbit $n$ is equal to $3$

$r=0.537\times 3\times 3$

$r=4.833A^0$

Therefore the radius of third orbit is $=4.833A^0$.