Chapter 8, Problem 1MC

To determine

The position of positive charge in an atom according to Rutherford’s atomic model.

Answer to Problem 1MC

Option (b) concentrated at its center

Explanation of Solution

Ernest Rutherford proposed the Rutherford’s model of atom. An atom has electrons, neutrons and protons as its components. The electrons are orbiting the nucleus in which the protons and neutrons are situated.

Proton has positive charge, neutron is charge less and electron has negative charge. Thus nucleus has positive charge and the orbit around the nucleus has negative charge. According to Rutherford’s atom model, the positive charge is concentrated at the center called as nucleus. Alpha particle has positive charge. However, the electrons will not influence the alpha particle scattering. The charge of nucleus depends on the number of protons.

Conclusion:

The protons are concentrated at the nucleus with neutral neutrons. Thus, positive charge is concentrated at the center of the atom. Thus, option (b) is correct.

The positive charge cannot spread throughout the volume. Since the protons are only situated inside the nucleus. Thus, option (a) is incorrect.

The positive charge will not reflect when alpha radiation comes in to the atom. The alpha particle get scattered from the center since the nucleus has positive charge. Thus, option (c) is incorrect.

The size of nucleus and number of protons differs with the atomic number. Thus, option (d) is incorrect.