Sodium-24 (1124Na^{24}_{11}\text{Na}1124Na) is a radioactive isotope that decays by emitting beta-minus (β−\beta^-β−) radiation.
a.[1]
Which of the following is the correct decay equation for Sodium-24?
- A: 1124Na→1224Mg+−1−0e^{24}_{11}\text{Na} \rightarrow {}^{24}_{12}\text{Mg} + {}^{\phantom{-}0}_{-1}\text{e}1124Na→1224Mg+−1−0e
- B: 1124Na→0920F+24He^{24}_{11}\text{Na} \rightarrow {}^{20}_{\phantom{0}9}\text{F} + {}^{4}_{2}\text{He}1124Na→0920F+24He
- C: 1124Na→1024Ne+−1−0e^{24}_{11}\text{Na} \rightarrow {}^{24}_{10}\text{Ne} + {}^{\phantom{-}0}_{-1}\text{e}1124Na→1024Ne+−1−0e
b.[2]
Use the graph below to determine the change in mass of the sample of Sodium-24 between 10 hours and 30 hours.
c.[1]
Use the graph to estimate the mass of Sodium-24 remaining after 40 hours.