He energy needed to keep a 75-watt lightbulb burning for 1.0 h is 240 kJ . Calculate the energy required to keep the lightbulb burning for 3.0 h in each of the following energy units. A, Joules
B. Kilocalories

B. nuclear reactions could first occur.

It starts to rust i think

Remember that rust prevented by placing a sacrificial electrode in electrical contact with the iron. the sacrificial electrode must be composed of a metal that  oxidizes  more easily than iron (that is, it must be below iron in table 18.1).

Polyethylene is a strong synthetic polymer that can be used to make toys and bottles. polyethylene is a plastic material called thermoplastic. one very useful property of thermoplastic is that when it is heated it turns into liquid, which can be molded into desired shape and size. also the material do not dissolve at room temperature.