Chapter 38, Problem 21A

To determine

Whether the momenta and positions of electrons in an atom be measured with certainty.

Explanation of Solution

Introduction:

According to Heisenberg’s principle, the measurement of momentum and position of an object s simultaneously is impossible.

The momenta and positions of the electron in an atom is analyzed by the principles of quantum mechanics. The mass of the electron is very less and the speed of the electron is very high in an atom. The momentum of an electron is the product of the mass and speed of the electron.

The mass and speed of the electron cannot be measured with certainty, so the momenta of the electron for various positions cannot be predicted with certainty. The prediction about the momenta and positions of the electron is based on the probability about the position of the electron in an atom.

Conclusion:

The momenta and positions of electrons in an atom cannot be measured with certainty.