For a particle of mass $0.02 \, kg$,the uncertainty in its velocity is $9.218 \times 10^{-6} \, m/s$. The uncertainty in its position is .......

The Heisenberg uncertainty principle can be applied to :

Based on Heisenberg's uncertainty principle,the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter $10^{-15} \ m$ is ............. $\times 10^9 \ ms^{-1}$ (nearest integer)
[Given : mass of electron $= 9.1 \times 10^{-31} \ kg$,Plank's constant $(h) = 6.626 \times 10^{-34} \ Js$ ]
(Value of $\pi = 3.14$ )

What is $\psi$ and what is $|\psi|^2$? What do they represent?

What is the value of $\Delta v \cdot \Delta x$ for an electron? What does it indicate?

Why was a change in the Bohr Model of atom required? Due to which important development$(s)$,was the concept of movement of an electron in an orbit replaced by the concept of probability of finding an electron in an orbital? What is the name given to the changed model of atom?