Saved Bookmarks
| 1. |
M_(x) and M_(y) denote the atomic masses of the parent and the daughter nuclei respectively in radioactive decay . The Q - value for a beta^(-) decay is Q_(1) and that for a beta^(+) decay is Q_(2). If m_(e) denotes the mass of an electron then which of the following statements is correct? |
|
Answer» `Q_1=(M_x-M_y)c^2` and `Q_2=(M_x-M_y-2m_e)c^2` `THEREFORE Q_1=[m_N(._ZX^A)-m_N(._(Z+1)Y^A)-m_e]c^2` `=[m_N(._ZX^A)+Zm_e-m_N(._(Z+1)Y^A) - (Z+1)m_e]c^2` `=[m(._ZX^A)-m(._(Z+1)Y^A)]c^2=(M_x- M_y)c^2` `beta^+` decay is represented as `._ZX^A=._(Z-1)Y^A + ._1e^0 + UPSILON + Q_2` `therefore Q_2=[m_N(._ZX^A)-m_N(._(Z-1)Y^A)-m_e]c^2` `=[m_N(._ZX^A)+Zm_e-m_N(._(Z-1)Y^A) - (Z-1)m_e-2m_e]c^2` `=[m(._ZX^A)-m(._(Z-1)Y^A)-2m_e] c^2=(M_x-M_y-2m_e) c^2` |
|