Question

Figure 18.43 shows the charge distribution in a water molecule, which is called a polar molecule because it has an inherent separation of charge. Given water’s polar character, explain what effect humidity has on removing excess charge from objects.

Figure 18.43 Schematic representation of the outer electron cloud of a neutral water molecule. The electrons spend more time near the oxygen than the hydrogens, giving a permanent charge separation as shown. Water is thus a polar molecule. It is more easily affected by electrostatic forces than molecules with uniform charge distributions.

Short answer

Humidity has high tendency to remove the excess charge from the objects due to its high interactive bonds or the polar nature of the molecules.

Step-by-step solution

Polar molecules

There are two types of molecules:

• Polar molecules
• Non-polar molecules

In polar molecules, due to difference between the electronegativity of the atoms the bonded electrons shift towards the more electronegative atom creating partially negative charge on them. On the other hand, partially positive charge is created on less electronegative atom.

Effect of humidity

Due to polar nature of water molecules, it has tendency to remove excess charge from the objects. When the humidity is high the concentration of water vapor in the atmosphere is high.

Thus, humidity increases the conductivity of the air. As a result objects in such environment will not be able to hold charge.