Final answer:
Hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) are better alternatives to CFCs due to their structure containing less or no chlorine, allowing them to break down more quickly and pose less risk to the ozone layer.
Step-by-step explanation:
A better alternative to chlorofluorocarbons (CFCs) are hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs), such as HFC-134a (CF3-CH2F) and HCFC-141b (CH2-CCl2F). The structure of these molecules differs from CFCs, most notably in that HFCs do not contain chlorine, and HCFCs contain less chlorine than CFCs. This is better for the environment because HCFCs and HFCs are less stable and break down more quickly in the lower atmosphere, which means that fewer of them reach the stratosphere to damage the ozone layer. For instance, the highly stable C-F bond found in Teflon makes it inert, whereas the presence of C-H bonds in HCFCs and HFCs causes them to decompose before reaching the stratosphere, thus posing less risk to the ozone layer. Replacing toxic and carcinogenic compounds like carbon tetrachloride (CCl4) with less harmful alternatives such as dichloromethane (CH2Cl2) also offers a better structure for health and environmental safety.