Explain why Lithium is a cation?

Unlike the other alkali metals, lithium has a single valence electron and can easily be delivered to form a cation. Of this reason, lithium is a strong heat and electricity conductor as well as a highly reactive element although it is the least reactive of alkali metals.

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.