Which of the following statements is true?
a. an ionic bond is formed through the sharing of electrons. once dissolved in water,
b. ionic compounds rarely conduct electricity.
c. an ionic bond is much stronger than most covalent bonds.
d. ionic compounds at room temperature typically conduct electricity. none of the above is true.

c. An ionic bond is much stronger than most covalent bonds

Explanation:

Ionic bonds are interatomic bonds that forms as a result of electrostatic attraction between two ions. For an ionic bond to be formed, one atom must have lost or gained electron from another that is transferring it. Ionic bonds typically form between atoms whose electronegativity differences are far apart.

Ionic bonds are usually stronger than other types of bonds due to the electrostatic attraction between ions.

One very distinct feature about ionic compounds is that they are conductors of electricity in either molten or aqueous. At room temperature, they are solids and contains no mobile ions.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer