Final answer:
The atomic number, which defines the element identity, is equal to the number of protons in the nucleus. Since the nucleus in question contains 6 protons, the atomic number is 6, which corresponds to the element carbon.
Step-by-step explanation:
The atomic number of an atom is defined by the number of protons it contains. In the given scenario, since the atomic nucleus contains 6 protons, the atomic number of the atom is 6.
The atomic number (Z) is the defining feature of an element and for any atom that contains 6 protons, we are referring to the element carbon, which has an atomic number 6. In a neutral atom, the number of protons is equal to the number of electrons to balance the positive and negative charges.
Therefore, with 2 electrons in the K shell and 4 electrons in the L shell, the atom maintains electrical neutrality, indicating that this configuration indeed corresponds to carbon, which possesses a total of 6 electrons when neutral.