A substance with a mass of 9 g absorbs 439.2 J of heat, and its temperature increases by 20 °C. Calculate its specific heat capacity and select the correct option.

The heat gained ($Q$) is $439.2 \text{ J}$.
The mass of the substance ($m$) is $9 \text{ g}$.
The change in temperature ($\Delta T$) is $20 \text{ °C}$.

The formula relating heat, mass, specific heat capacity, and temperature change is:

Where $c$ is the specific heat capacity. To find $c$, we rearrange the formula:

The calculated specific heat capacity is $2.44 \text{ J/g} \cdot \text{°C}$.
The options provided are:
1: 2.44
2: 4.18
3: 2.06
4: 0.449

The calculated value matches option 1.