Question

energy is released when we burn natural gas.

Explanation:

To determine the type of energy released when burning natural gas, we analyze the combustion process:

Step 1: Identify the reaction type

Burning natural gas (a hydrocarbon, primarily methane, $\ce{CH_4}$) is a combustion reaction. Combustion reactions involve reacting with oxygen ($\ce{O_2}$) and produce heat (and light) as energy.

Step 2: Determine the energy form

In combustion, chemical energy stored in the bonds of $\ce{CH_4}$ and $\ce{O_2}$ is converted into heat (thermal) energy (and light). The reaction is:
$$\ce{CH_4 + 2O_2 -> CO_2 + 2H_2O + \text{Heat (and light)}}$$

If the question is to identify the energy (e.g., "____ energy is released..."), the answer is Chemical (stored in bonds) is converted to thermal, but the blank likely expects "Chemical" (or "Thermal") based on context. Assuming the blank asks for the energy released (as thermal), or the energy source (chemical).

If the task is to fill the blank, the most accurate term for the energy released (the output) is Thermal (heat), but the energy source is Chemical. Depending on the question’s focus:

• If asking for the energy released (form): Thermal (Heat)
• If asking for the energy converted (source): Chemical

For example, if the blank is for the energy released (the energy we get), the answer is "Thermal" (or "Heat"). If for the energy stored in natural gas (the energy being converted), it’s "Chemical".

Assuming the question is about the energy released (the output of burning), the answer is:

Answer:

Thermal (or Chemical, depending on context; "Thermal" is the energy released, "Chemical" is the energy converted)

(Note: If the question is simply to identify the type of energy released, "Thermal" (heat) is the primary energy released during combustion.)