If pure baking soda is heated to great temperatures it transforms into a gas plus lighter but very alkaline solid Does this suggest that an element or compound?

The fact that pure baking soda (sodium bicarbonate) transforms into a gas (carbon dioxide) plus a lighter but very alkaline solid (sodium carbonate) when heated to great temperatures suggests that it is a compound.

When a compound undergoes a chemical change, it breaks down into simpler substances or transforms into new compounds. In the case of baking soda, the decomposition reaction can be represented as follows:

2NaHCO3 (sodium bicarbonate) → Na2CO3 (sodium carbonate) + H2O (water) + CO2 (carbon dioxide)

During this process, the sodium bicarbonate compound breaks down into three different substances: sodium carbonate (a solid), water (a liquid), and carbon dioxide (a gas). This indicates that baking soda is not an element, which is a pure substance that cannot be broken down into simpler substances by chemical means, but rather a compound composed of multiple elements chemically bonded together.