True or false. the solar wind is mainly made of protons and electrons.

The statement is True.

Explanation:

The solar wind is defined as a stream of energized, charged particles principally for protons and electrons. This solar wind can be measured by special equipments as the spacecraft. By the other hand the solar wind is the plasma that rise from the surface of the sun.  

By the other hand The protons and electrons together with the nuclei of heavier elements in smaller numbers are accelerated by the high temperatures of the solar corona.   (By Encyclopedia Britannica).