Final answer:
The expansion of a child's helium balloon during a heat wave is an example of Charles's Law, which states that gas volume is directly proportional to temperature at constant pressure. (option b)
Step-by-step explanation:
When a child's helium balloon increases in size during a heat wave, it is an example of Charles's Law. Charles's Law states that the volume of a given amount of gas is directly proportional to its temperature on the kelvin scale when the pressure is held constant. This can be observed when a balloon fills with air and is then subjected to an increase in temperature. As the temperature rises, the gas inside the balloon also warms up, causing the helium atoms to move around more quickly and expand, thus increasing the volume of the balloon.
The mathematical expression of Charles's Law is given by:
V∝T where V is the volume of the gas, and T is its absolute temperature.
In this scenario, as the temperature (T) increases, the volume (V) of the gas (helium) inside the balloon also increases, leading to the observed expansion.
The expansion of a helium balloon during a heat wave aligns with Charles's Law, which describes the relationship between the volume and absolute temperature of a gas at constant pressure. Therefore, the correct answer is b) Charles's Law.