Find the energy of third stationary orbit of Bohr's model of hydrogen atom if the energy of ground state is $-E$ J

Which of the following statements regarding Pi $(\pi)$ bond is NOT true ?

Identify the number of lone pair and bond pair electrons present in the valence shell of central atom in $\text{BrF}_3$.

A gas at $10\,^\circ\text{C}$ occupies a volume of 283 mL. if it is heated to $20\,^\circ\text{C}$ keeping the pressure constant. What is the new volume of gas ?