Em tham khảo nha :

\(\begin{array}{l}
a)\\
{m_C} = {m_p} + {m_n} + {m_e} = 6 \times 1,6726 \times {10^{ - 27}} + 6 \times 1,6748 \times {10^{ - 27}} + 6 \times 9,1094 \times {10^{ - 31}}\\
{M_C} = 2,009 \times {10^{ - 26}}kg\\
b)\\
{m_e} = 6 \times 9,1094 \times {10^{ - 31}} = 5,466 \times {10^{ - 30}}kg\\
\frac{{{m_e}}}{{{m_C}}} = \dfrac{{5,466 \times {{10}^{ - 30}}}}{{2,009 \times {{10}^{ - 26}}}} = 2,72 \times {10^{ - 4}} \approx 0\\

\end{array}\)

a)

$m_{C}$=$m_{p}$ +$m_{n}$+$m_{e}$=$6×1,6726×10^{-27}$ ++$6×9,1094×10^{−31}$

                                                    +$6×1,6748×10^{−27}$

⇒$M_{C}$=2,009×$10^{−26}$kg

b)$m_{e}=$6×9,1094×10^{−31}$=$5,466×10^{−30}$kg

$\frac{m_{e}}{m_{C}}$ =$\frac{5,466×10^{−30}}{2,009×10^{−26}}=$2,72×10^{−4}$≈0

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