Answer:
The answer is A. 8 protons, 8 electrons, and 8 neutrons.
Step-by-step explanation:
This is because Oxygen's atomic number is 8 and its atomic weight is 15.99 units. The atomic number is the number of protons in an atom. This means that there are 8 protons, along with 8 electrons, because the amount of electrons in an atom are equal to the number of protons (not including ions.) Additionally, to discover the amount of neutrons present in the given atom, you must take the atomic weight and subtract the atomic number (aka # of protons present). Once you subtract, you will be left with the number of neutrons. Since the atomic weight is 15.99, you will round it up to 16 and subtract 8, leaving 8 neutrons present. In all, it has 8 protons, 8 neutrons, and 8 electrons.