A radioactive series different from those shown in Figures...

A radioactive series different from those shown in Figures 28.14 and P28.25 begins with $^{90}_{232} \mathrm{Th}$ and undergoes the following series of decays: $\alpha \beta^{-} \beta^{-} \alpha \alpha \alpha \alpha \beta^{-} \alpha \beta^{-} .$ Determine each nucleus in the series.

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Key Concepts

Decay Series

A sequential chain of transformations initiated by a radioactive parent nucleus undergoing successive decays into different daughter nuclei until a stable isotope is reached. This concept is essential for tracking the changes in atomic and mass numbers in a nuclear decay chain.

Nuclear Transmutation

The process of altering one chemical element into another via changes in the nucleus, typically through processes like alpha and beta decay. It underpins the entire concept of decay series, where a chain of radioactive decays eventually leads to a stable element.

Beta Decay

A form of radioactive decay in which a nucleus emits a beta particle (an electron or positron). In beta-minus decay, a neutron transforms into a proton, increasing the atomic number by 1 without changing the mass number, while beta-plus decay decreases the atomic number by 1.

Alpha Decay

A type of radioactive decay where an unstable nucleus emits an alpha particle (two protons and two neutrons), resulting in a reduction of the atomic number by 2 and the mass number by 4. This is a key mechanism for transmutation in heavy elements.

Radioactive Decay

This is the process by which an unstable nucleus releases energy by emitting radiation, transforming into another nucleus. It is fundamental to understanding how elements change identity over time.

Transcript

00:04 Okay, problem 51.

00:08 So we have a radioactive series, and we'll have to find all the different atoms in the process.

00:18 So for examples of radioactive series, you can look at figures 28 .14 and figures nm p 28 .25 oh, problem 28 .25.

00:40 But we're going to have a different redirective series.

00:42 Ours start with thorium 90 3m has 2 wait that's a mistake in numerate for sure and this is flipped because the bigger number is always at the top okay so here it goes so we're gonna have alpha decay beta minus beta minus alpha alpha alpha alpha alpha beta minus so for alpha decay we we lose 4 at the top into the bottom.

01:40 So that's 88 and 228.

01:58 8 is radium.

02:24 Okay, then after that we have a beta minus.

02:28 So in a beta minus we just gain a proton.

02:40 So it becomes 228, 89.

02:52 Tinium.

03:00 And there's another beta minus.

03:03 And that goes back to thorium.

03:04 But 228 and alpha decay.

03:15 Make sure there's going to be four alpha decays now.

03:29 So after thorium decays, it's radium again.

03:33 But we're losing four at the top, so now it's 224 radium.