Question

draw the lewis dot diagram for a h+ cation.

Explanation:

A hydrogen atom has 1 electron. A $H^{+}$ cation is formed when a hydrogen atom loses its single - electron. Since there are no electrons left, its Lewis dot diagram has no dots.

Answer:

(No dots, just the symbol H with a + sign to represent the positive charge, e.g., $H^{+}$)