Final answer:
Carbon dioxide is a pure substance with carbon and oxygen chemically bonded in a fixed ratio, forming a stable molecule (CO2). It cannot be separated into its elements through physical methods, and it has a consistent composition across different samples.
Step-by-step explanation:
The gas carbon dioxide is indeed a pure substance, in which carbon and oxygen are chemically bonded to each other. This bonding forms a molecule with one carbon atom and two oxygen atoms, typically represented as CO2. Carbon dioxide has several important characteristics:
- Carbon and oxygen are chemically bonded within a carbon dioxide molecule.
- The atoms of carbon and oxygen do not retain their original properties since they are part of a compound with new chemical properties.
- Carbon dioxide, being a compound, cannot be separated into carbon and oxygen by physical means, but requires chemical reactions to break its bonds.
- The proportion of carbon to oxygen in carbon dioxide is always fixed at one atom of carbon to two atoms of oxygen, signifying its fixed chemical composition.
Carbon dioxide's structure is such that the carbon atom forms two double covalent bonds with the two oxygen atoms, firmly establishing it as a molecule with specific and consistent chemical properties. This stable composition means that regardless of the sample of carbon dioxide gas, it will always have the same ratio of carbon to oxygen, confirming it as a pure substance.