<P> A period is a horizontal row in the periodic table . Although groups generally have more significant periodic trends , there are regions where horizontal trends are more significant than vertical group trends , such as the f - block , where the lanthanides and actinides form two substantial horizontal series of elements . </P>
<P> A period is a horizontal row in the periodic table . Although groups generally have more significant periodic trends , there are regions where horizontal trends are more significant than vertical group trends , such as the f - block , where the lanthanides and actinides form two substantial horizontal series of elements . </P>
this is a horizontal arrangement of elements in the periodic table
this is a horizontal arrangement of elements in the periodic table
period
period