Chapter 17, Problem 55A

To determine

To identify: Whether the electrons or protons contributes more to an atom’s mass and an atom’s size.

Answer to Problem 55A

The proton contributes more to an atom’s mass and the electron contributes more to an atom’s size.

Explanation of Solution

Introduction:

The atom’s mass is mainly concentrated in its nucleus.

The volume occupied by the nucleus is less than a trillionth of the whole volume of an atom.

Protons in the atom’s nucleus are positive and electrons orbiting the nucleus are negative.

The number of electrons and number of protons are equal in an electrically neutral atom.

The mass of electron is $\frac{1}{1800}$ times the mass of proton.

A proton plays a vital contribution to the atom’s mass.

The weight of one proton is about 2000 times more than one electron and it is the equal numbers of protons and electrons in any neutral atom.

The electrons provides a major contribution to the atom’s size: the diameter of the atom is about 10000 times the nuclear diameter.

Hence, the proton contributes more to an atom’s mass and the electron contributes more to an atom’s size.

Conclusion:

Thus, the proton contributes more to an atom’s mass and the electron contributes more to an atom’s size.