Although physical and chemical changes can both result in a change of state, such as from liquid to gas or solid, the two processes are completely different. In a physical change, the matter simply undergoes a change in state, such as by freezing or being dissolved in water.Know More
However, the actual molecules in the substance remain chemically identical despite this change. This is the opposite of a chemical change, where the molecules undergo a chemical reaction that forms new chemical substances. This process is not reversible, as the actual chemical structure of the various atoms has been changed, unlike in a physical change, which can always be reversed. In chemical changes, the atoms in the substance always break apart or join together to form new compounds.
For instance, water can also be boiled to create steam or frozen to create ice, but each of these substances still have the same chemical makeup, H20. However, when gasoline is burned, the result is two new substances, carbon dioxide and water vapor. Similarly, when iron is exposed to oxygen, the two react to form iron oxide, or rust. Although the layers of iron underneath the rust are still pure, the chemical change at the surface is permanent, as the iron oxide cannot be changed back into pure iron.Learn more about Chemistry
Liquefied natural gas is an odorless liquid that is formed when natural gas is cooled to -260 degrees Fahrenheit. It is also non-toxic, and the liquefaction process shrinks the volume of the gas 600 times, which makes it easier to ship abroad.Full Answer >
The graph of Charles Law is a graph describing how the volume of a gas changes with respect to its temperature and where the volume is a linear function of the temperature. When the temperature of gas is given in units of Kelvin, the graph intersects the x-axis at 0 K, where the volume is 0. On the other hand, if the temperature is given in units of Celsius, the graph intersects -273 degrees Celsius on the x-axis.Full Answer >
Harper College explains that forming a precipitate, color changes, gas formation and temperature change are signs of a chemical change. The University of California, Davis adds that the presence of odor also indicates a chemical change. There are only five indicators of a chemical change.Full Answer >
The kinetic energy of gas molecules is directly proportional to changes in temperature. When temperature increases, the kinetic energy of the gas molecules also increases; conversely, when the temperature decreases, the gas molecules' kinetic energy also decreases.Full Answer >