An atom with 12 electrons, 13 neutrons, and 11 protons would be the isotope of aluminum, specifically aluminum-24.
The atomic number of an element corresponds to the number of protons in the nucleus, which in this case is 11 for aluminum. The number of electrons in a neutral atom is equal to the number of protons, so there are 11 electrons.
The atomic mass of an atom is the sum of its protons and neutrons, so aluminum-24 would have a total of 11 protons (giving it its atomic number), 13 neutrons, and therefore an atomic mass of 24.
Aluminum is a common element found in many everyday objects, such as foil, cans, and various construction materials. Different isotopes of aluminum exist with varying numbers of neutrons, resulting in different atomic masses.