Answer:
D
Explanation:
One of the properties of metals is their abilities to form a stable compounds by losing electron(s). Metals form positive ions (cations) when they lose electron(s).
I believe the answer is C.
N203 is the answer, if i am wrong im sorry!
D is correct.
Another equivalent explanation currently used is the watermelon. Thomson believed (if using the watermelon as an example) that the red part, was some kind of positive matter and the seeds where electrons - electrons stuck to a positively charged matter.
Hope it helped,
Happy homework/ study/ exam!