Chapter 28, Problem 1RCQ

To determine

The effect of incident light that falls on an object affect the motion of electrons in the atoms of the object

Answer to Problem 1RCQ

Solution:

The light incident on an object can be absorbed, reflected or transmitted by the electrons in the atoms of the object.

Explanation of Solution

When light with a certain frequency is incident on an object it can be absorbed, reflected or transmitted by the electrons in the atoms of the object. It depends on the frequency of incident light. If Sunlight is incident which contains several frequencies only some of them are absorbed and the remaining are reflected or transmitted. If the frequency of incident light equals the natural frequency of electrons of an atom in the object then the light is absorbed, and the electrons begin to vibrate. This vibrational energy is then converted into thermal energy..

Sometimes an object may have several types of atoms having different natural frequencies. If Sunlight is incident on this type of object with many frequencies a range of frequencies may be absorbed by the object. The incident frequency which is not equal to the natural frequency of atoms in the object can be transmitted or reflected. When this frequency is incident the electrons begin to vibrate with small amplitude. If the object is transparent then this vibration energy is given to neighboring atoms and finally, a light wave is transmitted through the other side of the object. If the object is opaque, then the vibration energy cannot be shared with neighboring atoms and hence, the light is reflected through the incident side of the object.

Conclusion:

When light with many frequencies are incident on an object, some of them are absorbed by the object and the remaining are transmitted or reflected depending on the incident frequencies.