Which element is used as the trendsetter element?

This question is incomplete

Explanation:

This question is incomplete. However, trendsetter elements can be described as the element in which other elements are compared to as regards to a particular property; this could be as a result of the element's distinct and absoluteness of such property or as a result of the element's neutrality of such property. For example, in the electrochemical series, hydrogen can be described as the trendsetter element because hydrogen as a standard reduction potential (E°) of 0.00, thus elements above hydrogen in the series are positively charged while those below hydrogen in the series are negatively charged.