chemistry unit 4 practice questions\n1. consi...
chemistry unit 4 practice questions\n1. consider the decay series for 226ra, which ends in the formation of 210pb.\nwhat is the correct order of isotopes formed during this decay?\na. 218po, 222rn, 210tl, 214bi, 214pb\nb. 222rn, 218po, 214pb, 214bi, 210tl\nc. 214pb, 210tl, 214bi, 218po, 222rn\nd. 210tl, 214bi, 214pb, 222rn, 218po
Answer
# Explanation:
## Step1: Recall radium - 226 decay series
Radium - 226 ($^{226}Ra$) undergoes a series of alpha and beta decays to reach lead - 210 ($^{210}Pb$). The decay sequence involves the following main steps: $^{226}Ra$ decays to radon - 222 ($^{222}Rn$) by alpha decay. Then $^{222}Rn$ decays to polonium - 218 ($^{218}Po$) by alpha decay. $^{218}Po$ can decay to lead - 214 ($^{214}Pb$) by alpha decay. $^{214}Pb$ decays to bismuth - 214 ($^{214}Bi$) by beta decay. $^{214}Bi$ can decay to thallium - 210 ($^{210}Tl$) by beta decay.
## Step2: Match with options
By comparing the above - mentioned decay sequence with the given options, we find that the correct order of isotopes formed during the decay of $^{226}Ra$ to $^{210}Pb$ is $^{222}Rn$, $^{218}Po$, $^{214}Pb$, $^{214}Bi$, $^{210}Tl$.
# Answer:
b. $^{222}Rn$, $^{218}Po$, $^{214}Pb$, $^{214}Bi$, $^{210}Tl$