Answer is: formula of the complex is [Cr(NH₃)₂(SCN)₄<span>]</span>⁻<span>.
This complex has negative charge (-1) because chromium (central atom or metal) has oxidation number +3, first ligand ammonia has neutral charge and second ligand thiocyanate has negative oxidation number -1:
+3 + 2</span>·0 + 4·(-1) = -1.
<span>'It is formed when metal atoms lose electrons to nonmetal atoms' is the incorrect statement. This statement is the definition of ionic bonding.
Hope this helps!</span>