Final answer:
The collision of a carbon-12 atom with a helium-4 atom results in an oxygen atom with atomic number 8, mass number 16, possessing 8 protons, 8 neutrons, and 8 electrons.
Step-by-step explanation:
When an atom of carbon-12 is collided with an atom of helium-4, the new element formed would have an atomic number equal to the sum of the number of protons in both original atoms. Carbon has 6 protons and helium has 2 protons, giving the new element 6 + 2 = 8 protons. This element is oxygen (O), as oxygen is the element with atomic number 8.
The mass number of the new element would be the sum of the mass numbers of carbon-12 and helium-4. This gives us a mass number of 12 + 4 = 16. Hence, the new element would be oxygen-16. In a neutral atom, the number of electrons is equal to the number of protons, which means the new oxygen atom would have 8 electrons.
Since we started with carbon-12, the number of neutrons was 6 (mass number 12 - number of protons 6 = 6 neutrons). Helium-4 has 2 neutrons, so the new oxygen atom would also have 6 + 2 = 8 neutrons. Therefore, the complete characteristics of the new element would be: element oxygen (O), atomic number 8, mass number 16, with 8 protons, 8 neutrons, and 8 electrons.