Firstly, it should be noted that atomic number (number of protons) determines element. And the element with the atomic number 10 (10 protons) is Neon. Hence, Neon-10 (₁₀Ne) is the answer.
Note that sodium has an atomic number of 11. Also, number of protons is usually equal to the number of electrons in neutral atoms, this is because the total number of positive particles (protons) must be equal to the total number of negative particles (electrons) to give a neutral atom.
The Group 3A metals have three valence electrons in their highest-energy orbitals (ns2p1). They have higher ionization energies than the Group 1A and 2A elements, and are ionized to form a 3+ charges. The Group 3A metals are silvery in appearance, and like all metals are good conductors of electricity.
