Chemical change happens when a substance combines with
another substance to form a new substance. It produces chemical reactions and
generally is not reversible except by further chemical reactions. Heat is sometimes
produced in some reactions. When chemical reactions occur, the atoms are
rearranged and an energy change happens along with it as new products are
generations. At a molecular level, chemical changes involves the making or
breaking of bonds between atoms. Some examples of chemical change are iron
rusting (iron oxide forms) and bread rising (yeast converts carbohydrates into
carbon dioxide gas).
Thermal energy causes of motion of
1. mixing water molecules contained in a beaker.
2.<span>molecules in soild liquid and gas phases
3. mixing </span><span>molecules together
4. </span><span>molecules that have reached equilibrium </span>
The focal length, like you said it's the distance between the FOCAL point and the mirror.
Hope this helps.... :)
An example of habitat destruction could be a squirrel who lives in a tree but modern civilication cutting down the squirrels tree and leaving it homeless