PLS HELP 1) Why do some ionic compound names have Roman numerals in them?
a. To indicate the charge on the ionic compound.
b. To indicate the total number of atoms in a compound.
c. To indicate how many anions are present.
d. To indicate the charge on the cation.

2) What is the formula for Magnesium oxide?
a. MgO
b. MgO2
c. Mg2 O2
d. Mg2

3) How can you determine the charge of an ion formed by a representative element?
a. An ion's charge is always 1/2 the atomic number.
b. The charge of the ion formed is related to the element's group number.
c. The charge of the ion is related to the element's period number.
d. The charge of the ion is the number of valence electrons minus the number of core electrons.

4) How do Ca2+ and phosphate, (PO4) 3- combine to make an electrically neutral compound?
a. Two Ca2+ ions combine with three (PO4)3- ions. ions
b. Three Ca ions combine with two P ions and eight O ions.
c. Three Ca2+ ions combine with two (PO4)3- ions.
d. You add all of the electrons together and divide by two.

5) What is the formula for lithium fluoride?
a. LiF2
b. LiF
c. Li3 F2
d. Li2 F