( ) is the wearing away of metals due to a chemical reaction, commonly known as rusting.

Label each of the following as either a physical process or a chemical process:(a)rusting of a metal can is a process;(b)boiling a cup of wateris a process;(c)pulverizing an aspirinis a process;(d)digesting a candy baris a process;(e)exploding of nitroglycerinis a process.

The intermediate bearing of the shafting is divided into upper and lower halves, which are fixed by bolts, so that it is convenient to_____. A: shafting installation and bearing wear inspection B: transmit torque C: improve the lubrication capacity of shafting D: prevent shafting from rusting