Give the difference between $\psi$ and $|\psi|^2$.

The possibility of finding an electron in an orbital was conceived by

In a $He$ atom,the uncertainty in the position of an $e^-$ is equal to the uncertainty in its momentum $\Delta p$. If the value of $\Delta p$ for the $e^-$ is $32 \times 10^5$,then the value of $\Delta p$ for the $He$ atom is .....

The uncertainties in the velocities of two particles,$A$ and $B$ are $0.05 \ ms^{-1}$ and $0.02 \ ms^{-1}$ respectively. The mass of $B$ is five times that of the mass of $A$. What is the ratio of uncertainties $\frac{\Delta x_A}{\Delta x_B}$ in their positions?

Assertion : It is impossible to determine the exact position and exact momentum of an electron simultaneously.
Reason : The path of an electron in an atom is clearly defined.

$A$ table-tennis ball has a mass of $10 \ g$ and a speed of $90 \ m/s$. If the speed can be measured within an accuracy of $4\%$,what will be the uncertainty in speed and position?