Which elements would be the equivalent of the noble gases? Express your answers as chemical symbols. Enter your answers in order of increasing atomic number separated by commas.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom

The answer is a) carbon-12