ANSWER
The correct answer is A
EXPLANATION
Plants manufacture their on food by the process of photosynthesis. During this process, plants trap radiant energy from the sun by the help of chlorophyll in the leaves.
Radiant energy with other raw materials such as water, carbon dioxide and mineral salts is converted to food (in the form of starch) which contains chemical energy.
The ion N³⁻ is called the azide ion. In its neutral state, it occurs as the element Nitrogen. The atomic number of Nitrogen is 7. When it turns into an anion (negatively charged ion), it gains 3 more electrons. That's why its net charge becomes -3. It means that the protons is still 7, but the electrons are now 10.
Overall charge = +7 + -10 = -3
