1. explain why oxygen gas must be written as o2 in a chemical equation.

Explanation:

So there are two reasons to write it as O2: 1. O2 is almost always the form of oxygen in a reaction, and 2. One needs to specify the form to describe how it will react. Other elements that usually exist as diatomic molecules are written as the dimer for the same reasons.

hope this helps!

b.

explanation:

10.0

laticia draws the diagram below to show earth’s magnetic field.

answer

the arrows to the right of earth should point up.