1³+3³=28

k nha minh nham!

\(\left\{{}\begin{matrix}p+e+n=82\\n-p=4\\p=e\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2p+n=82\\n-p=4\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}p=e=26\\n=30\end{matrix}\right.\)

M = p + n = 26 + 30 = 56 => M là nguyên tố sắt (Fe)

100 : 5 x 0 = 0