Problem $7(4$ pts$)$:Element X has a half$-$life of $30$ minutes. Which of the following statements is trues element X after $120$ minutes?A$)$ There will be $2$ nuclei left.B$)$ There is a $50\%$ chance the last remaining nucleus will have decayedC$)$ There will be $1$ nuclei left.D$)$ Half of the last remaining nucleus will decay