In the following list, only is not an example of a chemical reaction. the production of hydrogen gas from water the tarnishing of a copper penny chopping a log into sawdust charging a cellular phone burning a plastic water bottle

Option (c) is the correct answer.

Explanation:

A chemical reaction is defined as the reaction where a chemical bond will break in order to form a new bond due to the formation of a new substance.

For example,

Here, NaCl is the new substance that is formed. A chemical reaction will always bring change in chemical composition of a substance.

The production of hydrogen gas from water, the tarnishing of a copper penny, charging a cellular phone and burning a plastic water bottle are all chemical reactions.

Whereas a reaction where no change in chemical composition of a substance takes place is known as a physical reaction.

For example, chopping a log into sawdust will change the shape but it will not bring any change in chemical composition of the substance.

Thus, we can conclude that in the following list, only chopping a log into sawdust is not an example of a chemical reaction.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.