12. complete each of the following word equations for synthesis reactions. a. sodium + oxygen -> b. magnesium + fluorine -> 13. complete and balance the equations for the decomposition reactions. a. hgo -> [with the triangle heat symbol above the arrow] b. h2o(l) -> [with "electricity" written above the arrow]

Explanation:

12)

a) Sodium + oxygen = ?

When sodium reacts oxygen its forms sodium oxide as a product.

b) magnesium + fluorine = ?

When magnesium reacts with fluorine its forms magnesium fluoride as a product.

13)

a)

Decomposition of mercury(II) oxide on heating gives out mercury and oxygen gas.

b)

The electrolytic decomposition of water gives out hydrogen gas amd oxygen gas.