Answer: The answer is Cu+ P4 = Cu3P2
Which after balancing would be, 6Cu + P4 = 2Cu3p2
Explanation: Copper (Cu) is a metal and Phosphorous (P) is a non-metal. Metals and Non-metals combine to form ionic compounds where there is a transfer of ions from metal to non-metal.
Phosphorous has 5 valence electrons in its outer shell and Copper has 2 valence electrons. Following the octet rule, which means that the outer shell should have 8 electrons to be complete we see that combining these two metals on combining have electrons insufficient so we combine till we reach the octet structure. In this case, it happens when there are three copper and two phosphorous. We see that there are no more valence electrons. So it forms Copper II Phosphide, where the two indicates the charge of Copper.
Then we move on to balance both the sides of the equation, upon placing one number after the other to make the numerical value of elements equivalent to the other. Which gives us the answer.