If you want to know where the data comes from for any particular property, then select that property. You'll see graphs for the properties as well. Values for abundances are difficult to determine with much certainty, so all values should be treated with some caution, especially so for the less common elements. Here are a few comments about the biological role of thallium. Thallium has no biological role.
Thallium compounds are extremely toxic.
Their effects are cumulative and they can be absorbed though the skin. Thallium poisoning takes several days to act and it affects the nervous system. Sorry, your Browser does not support JavaScript and so you will not be able to use this calculator. Just enter your weight in either kilograms or pounds. In some browsers, after entering your weight you may have to click outside the text entry box to make the calculation work.