An electron is moving with a velocity of $600 \, m/s$ with an accuracy of $0.005\%$. The uncertainty in its position will be: ($h = 6.6 \times 10^{-34} \, kg \, m^2 \, s^{-1}$,mass of electron $m_e = 9.1 \times 10^{-31} \, kg$)

What is quantum mechanics? Give its primary information.

The position of both an electron and a helium atom is known within $1.0 \, nm$ and the momentum of the electron is known within $50 \times 10^{-26} \, kg \, m \, s^{-1}$. The minimum uncertainty in the measurement of the momentum of the helium atom is

Given below are two statements:
Statement $I:$ According to Bohr's model of hydrogen atom,the angular momentum of an electron in a given stationary state is quantised.
Statement $II:$ The concept of electron in Bohr's orbit,violates the Heisenberg uncertainty principle.
In the light of the above statements,choose the most appropriate answer from the options given below:

What is the quantum mechanical model of the atom? Give its important features.

The uncertainty in the position of an electron $(\Delta x)$ is approximately $100 \ pm$. Calculate the uncertainty in momentum $(\Delta p)$ of the electron in $kg \ m \ s^{-1}$. $[h = 6.626 \times 10^{-34} \ J \ s]$