147765 If ${ }_{92} \mathrm{U}^{238}$ changes to ${ }_{85} \mathrm{At}^{210}$ by a series of $\alpha$ - and $\beta$-decays, the number of $\alpha$ and $\beta$-decays undergone respectively is

147766 The half-life of a radioactive element is $10 \mathrm{~h}$. The fraction of initial radioactivity of the element that will remain after $40 \mathrm{~h}$ is

147770 In the nuclear reaction: ${ }_{92} \mathrm{U}^{238} \rightarrow{ }_{82} \mathrm{~Pb}^{206}$ the number of $\alpha$ and $\beta$ particles emitted are

147776 The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an

147765 If ${ }_{92} \mathrm{U}^{238}$ changes to ${ }_{85} \mathrm{At}^{210}$ by a series of $\alpha$ - and $\beta$-decays, the number of $\alpha$ and $\beta$-decays undergone respectively is

147766 The half-life of a radioactive element is $10 \mathrm{~h}$. The fraction of initial radioactivity of the element that will remain after $40 \mathrm{~h}$ is

147770 In the nuclear reaction: ${ }_{92} \mathrm{U}^{238} \rightarrow{ }_{82} \mathrm{~Pb}^{206}$ the number of $\alpha$ and $\beta$ particles emitted are

147776 The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an

147765 If ${ }_{92} \mathrm{U}^{238}$ changes to ${ }_{85} \mathrm{At}^{210}$ by a series of $\alpha$ - and $\beta$-decays, the number of $\alpha$ and $\beta$-decays undergone respectively is

147766 The half-life of a radioactive element is $10 \mathrm{~h}$. The fraction of initial radioactivity of the element that will remain after $40 \mathrm{~h}$ is

147770 In the nuclear reaction: ${ }_{92} \mathrm{U}^{238} \rightarrow{ }_{82} \mathrm{~Pb}^{206}$ the number of $\alpha$ and $\beta$ particles emitted are

147776 The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an

147765 If ${ }_{92} \mathrm{U}^{238}$ changes to ${ }_{85} \mathrm{At}^{210}$ by a series of $\alpha$ - and $\beta$-decays, the number of $\alpha$ and $\beta$-decays undergone respectively is

147766 The half-life of a radioactive element is $10 \mathrm{~h}$. The fraction of initial radioactivity of the element that will remain after $40 \mathrm{~h}$ is

147770 In the nuclear reaction: ${ }_{92} \mathrm{U}^{238} \rightarrow{ }_{82} \mathrm{~Pb}^{206}$ the number of $\alpha$ and $\beta$ particles emitted are

147776 The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an