what is the formula for the arsenic ion. A. As3-

Question

B. As2-
C. As,
D. As3+

I say c.

Answer 1

As has valences of +3, -3, and +5. Choice c is not an ion.
As is +3 in compounds such as As2O3. I would go with D as the better choice between A and D but A can be corrrect in some circumstances.