The answer is C I believe.
Answer: Ionic formula will be 
.
Explanation: 
and 
ions will form a ionic compound. Ionic compounds have both metals and non-metals.
Here is a metal and is a non-metal.
The net charge on any compound must be 0.
So we need 2 phosphate ions to balance the charge on ions. Similarly we need 3 Magnesium ions to balance the charge on ions.
Criss-crossing the charges, we will get the formula as
Criss-crossing is shown in the image below.
A. good conductors is not a characteristic of metals out of all the other followings.
Answer:
At No is 6 ... By definition the Atomic Number of an element is defined by the number of protons in its nucleus.
Explanation:
At No => #protons in nucleus
At Mass => ∑(#p⁺ + #n°); n° = no. neutron in nucleus.
