Answer:
The correct answer is 10 core electrons and one valence electron.
Explanation:
The electrons in an atom, which are not valence and do not take part in chemical bonding are known as core electrons. The core electrons and the nucleus of an atom produces the atomic core. These core electrons are held tightly with the nucleus. On the other hand, the outer shell electrons, which are associated with an atom and take part in the generation of a chemical bond is the outer shell is open are known as valence electrons.
In the given question, the atomic number of an element is 11, thus, the electronic configuration will be,
1S² 2S² 2P⁶ 3S¹
Hence, there is only one valence electron and 10 core electrons.
