Answer:
A is Carbon atom ; B is Nitrogen C is Nitrogen D is oxygen
Explanation:
A is is isotope of Carbon atom with proton 6 electrons and 8 neutrons, B is Nitrogen atom with 7 protons and 7 neutrons, C is Isotope of Nitogen with 7 protons and 8 neutrons and D is isotope of oxygen with 8 protons and 7 neutrons.
