Using dots and cross diagram show the compound phosphonium ion PH4 +(H=1,P=15)

To illustrate the compound phosphonium ion (PH4+), we can use a dots and cross diagram. In this diagram, dots represent electrons from hydrogen atoms (H) while crosses represent electrons from phosphorus atom (P). The positive charge on the phosphonium ion is indicated by a "+" sign.

Phosphonium ion (PH4+):
H H H
P : : :
H

In this diagram, the phosphorus (P) atom is located in the center while the four hydrogen (H) atoms are attached to it. Each hydrogen atom contributes one electron, represented by a dot. The phosphorus atom contributes five electrons, represented by crosses. The cross and dot pairs indicate that covalent bonds are formed between each hydrogen atom and the phosphorus atom. The overall structure of the phosphonium ion (PH4+) is tetrahedral, where the four hydrogen atoms are arranged around the central phosphorus atom.

(Note: The diagram may not be perfectly aligned due to formatting constraints. However, it still represents the arrangement of the atoms and electrons in the phosphonium ion.)