* Metals lack carbon: Metals are elements, and they don't contain carbon in their structure. Carbon dioxide (CO₂) is formed when carbon combines with oxygen.

* Metal oxides: When metals burn, they react with oxygen to form metal oxides. For example, iron (Fe) reacts with oxygen to form iron oxide (Fe₂O₃), which is commonly known as rust.

Here's a breakdown of the combustion process for metals:

1. Heat: When a metal is heated to a high enough temperature, it starts to react with oxygen in the air.

2. Oxidation: The metal atoms lose electrons and form positively charged ions, while oxygen gains electrons and forms negatively charged ions.

3. Metal Oxide Formation: These ions combine to form a metal oxide.

Examples:

* Magnesium: Burning magnesium produces a bright white light and forms magnesium oxide (MgO).

* Copper: Burning copper produces a green flame and forms copper oxide (CuO).

In summary: Metals burn to form metal oxides, not carbon dioxide. The presence of carbon is essential for the formation of CO₂ during combustion.