Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Radiogenic nuclide
Table title:
Radiogenic nuclides used in geology
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Parent nuclide </th><th colspan=1 rowspan=1 > Daughter nuclide </th><th colspan=1 rowspan=1 > Decay constant (yr−1) </th><th colspan=1 rowspan=1 > Half-life </th></tr>
<tr> <td colspan=1 rowspan=1 > 190Pt </td><td colspan=1 rowspan=1 > 186Os </td><td colspan=1 rowspan=1 > 1.477 ×10−12 </td><td colspan=1 rowspan=1 > 469.3 Gyr * </td></tr>
<tr> <td colspan=1 rowspan=1 > 147Sm </td><td colspan=1 rowspan=1 > 143Nd </td><td colspan=1 rowspan=1 > 6.54 ×10−12 </td><td colspan=1 rowspan=1 > 106 Gyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 87Rb </td><td colspan=1 rowspan=1 > 87Sr </td><td colspan=1 rowspan=1 > 1.402 ×10−11 </td><td colspan=1 rowspan=1 > 49.44 Gyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 187Re </td><td colspan=1 rowspan=1 > 187Os </td><td colspan=1 rowspan=1 > 1.666 ×10−11 </td><td colspan=1 rowspan=1 > 41.6 Gyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 176Lu </td><td colspan=1 rowspan=1 > 176Hf </td><td colspan=1 rowspan=1 > 1.867 ×10−11 </td><td colspan=1 rowspan=1 > 37.1 Gyr </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 232Th </td><td class="highlighted"  colspan=1 rowspan=1 > 208Pb** </td><td colspan=1 rowspan=1 > 4.9475 ×10−11 </td><td colspan=1 rowspan=1 > 14.01 Gyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 40K </td><td colspan=1 rowspan=1 > 40Ar </td><td colspan=1 rowspan=1 > 5.81 ×10−11 </td><td colspan=1 rowspan=1 > 11.93 Gyr </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 238U </td><td class="highlighted"  colspan=1 rowspan=1 > 206Pb** </td><td colspan=1 rowspan=1 > 1.55125 ×10−10 </td><td colspan=1 rowspan=1 > 4.468 Gyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 40K </td><td colspan=1 rowspan=1 > 40Ca </td><td colspan=1 rowspan=1 > 4.962 ×10−10 </td><td colspan=1 rowspan=1 > 1.397 Gyr </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 235U </td><td class="highlighted"  colspan=1 rowspan=1 > 207Pb** </td><td colspan=1 rowspan=1 > 9.8485 ×10−10 </td><td colspan=1 rowspan=1 > 0.7038 Gyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 129I </td><td colspan=1 rowspan=1 > 129Xe </td><td colspan=1 rowspan=1 > 4.3 ×10−8 </td><td colspan=1 rowspan=1 > 16 Myr </td></tr>
<tr> <td colspan=1 rowspan=1 > 10Be </td><td colspan=1 rowspan=1 > 10B </td><td colspan=1 rowspan=1 > 4.6 ×10−7 </td><td colspan=1 rowspan=1 > 1.5 Myr </td></tr>
<tr> <td colspan=1 rowspan=1 > 26Al </td><td colspan=1 rowspan=1 > 26Mg </td><td colspan=1 rowspan=1 > 9.9 ×10−7 </td><td colspan=1 rowspan=1 > 0.7 Myr </td></tr>
<tr> <td colspan=1 rowspan=1 > 36Cl </td><td colspan=1 rowspan=1 > 36Ar/S </td><td colspan=1 rowspan=1 > 2.24 ×10−6 </td><td colspan=1 rowspan=1 > 310 kyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 234U </td><td colspan=1 rowspan=1 > 230Th </td><td colspan=1 rowspan=1 > 2.826 ×10−6 </td><td colspan=1 rowspan=1 > 245.25 kyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 230Th </td><td colspan=1 rowspan=1 > 226Ra </td><td colspan=1 rowspan=1 > 9.1577 ×10−6 </td><td colspan=1 rowspan=1 > 75.69 kyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 231Pa </td><td colspan=1 rowspan=1 > 227Ac </td><td colspan=1 rowspan=1 > 2.116 ×10−5 </td><td colspan=1 rowspan=1 > 32.76 kyr </td></tr>
<tr> <td colspan=1 rowspan=1 > 14C </td><td colspan=1 rowspan=1 > 14N </td><td colspan=1 rowspan=1 > 1.2097 ×10−4 </td><td colspan=1 rowspan=1 > 5730 yr </td></tr>
<tr> <td colspan=1 rowspan=1 > 226Ra </td><td colspan=1 rowspan=1 > 222Rn </td><td colspan=1 rowspan=1 > 4.33 ×10−4 </td><td colspan=1 rowspan=1 > 1600 yr </td></tr>
</table>
Question:
How are 206Pb, 207PB and 208PB formed?
Answer:
The ²⁰⁶Pb is formed from ²³⁸U, ²⁰⁷Pb from ²³⁵U and ²⁰⁸Pb from ²³²Th.