If the mass number of 'A' is 230, then what is the mass number of 'H'? — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

**Step 1: Identify how each decay type changes mass number.** - Alpha decay ($-\alpha$): mass number $A$ decreases by 4 - Beta decay ($-\beta$): mass number $A$ is **unchanged** **Step 2: Count the alpha and beta decays in the chain.** $$A \xrightarrow{-\alpha} B \xrightarrow{-\alpha} C \xrightarrow{-\beta} D \xrightarrow{-\beta} E \xrightarrow{-\alpha} F \xrightarrow{-\beta} G \xrightarrow{-\alpha} H$$ | Transition | Type | $\Delta A$ | |---|---|---| | A → B | $\alpha$ | $-4$ | | B → C | $\alpha$ | $-4$ | | C → D | $\beta$ | $0$ | | D → E | $\beta$ | $0$ | | E → F | $\alpha$ | $-4$ | | F → G | $\beta$ | $0$ | | G → H | $\alpha$ | $-4$ | **Total alpha decays = 4**, total beta decays = 3. **Step 3: Calculate mass number of H.** $$A(H) = A(A) - 4 \times 4 = 230 - 16 = 214$$ **Answer: B — The mass number of nuclide H is 214.**