Atomic number =\\\\( P =8\\\\) Atomic Mass =\\\\( N+P=17\\\\) \\\\(N=9\\\\) Total no. of Neutrons = \\\\(9\ imes 12\ imes 10^{25}\\\\) =\\\\(\\dfrac{9\ imes 12\ imes 10^{25}\ imes N_{A}}{6\ imes 10^{23}}\\\\) \\\\(=1800N_{A}\\\\)Hence, the correct option is C.