Iso-butane and butane have different boiling points because of their molecular structures. Iso-butane has a branched structure, which allows its molecules to pack more closely together, resulting in stronger intermolecular forces. This makes it more difficult to overcome these forces and reach the boiling point compared to butane, which has a linear structure with weaker intermolecular forces. As a result, iso-butane has a higher boiling point than butane. **

Propane is a cleaner-burning fuel compared to butane, making it a more environmentally friendly option. It also tends to perform better in colder temperatures, making it a more reliable choice for outdoor activities in various weather conditions. Additionally, propane is widely available and can be used in a variety of appliances, making it a versatile fuel option for camping, cooking, and heating. **

Old Butane is a term used to describe butane that has been stored for a long period of time and has degraded in quality. Over time, butane can lose its potency and become less effective for use in lighters, stoves, and other applications. Old Butane may also develop impurities or contaminants that can affect its performance and safety. It is important to use fresh, high-quality butane for optimal results. **

No fusion occurs beyond iron in stars because the fusion of elements beyond iron requires more energy than it releases. Iron has the highest binding energy per nucleon, so fusing lighter elements into iron releases energy, but fusing iron into heavier elements requires an input of energy. As a result, once a star's core is mostly iron, the energy required to fuse iron into heavier elements is not available, and the star can no longer sustain nuclear fusion. This leads to the collapse of the star and the subsequent explosion in a supernova. **

Fusion does not occur over iron in stars because iron has the highest binding energy per nucleon of all the elements, meaning that it is very stable and requires more energy to fuse than it releases. As a result, fusing iron nuclei together actually consumes energy rather than releasing it, making it an unfavorable process in terms of energy production. This is why stars cannot sustain fusion reactions involving iron in their cores and eventually reach the end of their life cycle. **

Yes, butane is lighter than air. Butane is a gas that is less dense than air, which means it will rise and disperse in the atmosphere. This property makes butane highly flammable and a common choice for use in lighters. **

Butane can be burned by using a butane torch or lighter. To use a butane torch, you would first need to fill the torch with butane fuel, following the manufacturer's instructions. Then, you would ignite the torch using the ignition switch and adjust the flame to the desired size. To use a butane lighter, you would simply need to press the ignition button to release the butane gas and ignite it with the built-in spark. Always use caution when handling and burning butane to prevent accidents or injuries. **

Butane gas is typically stored in pressurized metal containers, such as canisters or cylinders. These containers are designed to safely hold the gas under pressure, preventing leaks and ensuring its stability. The containers are often equipped with valves and seals to control the release of the gas and to allow for safe usage. It is important to store butane gas containers in a well-ventilated area away from heat sources and open flames to prevent the risk of fire or explosion. **