When water used to cool power plants during normal plant operations is released into adjacent waterways, which of the following is most likely to occur as a result?

The number of valence electrons increases from the left to right across a period.The number of valence electrons stays the same from the top to the bottom of a group.Electrons are added into the outermost s orbital in Groups 1 and 2.Electrons are added into the outermost d orbital in Groups 3 through 12.Electrons are added into the outermost p orbital in Groups 13 through 18.