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 tantalum.
Tantalum has no biological role.
Possibly some tantalum compounds cause tumours. 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. Elements for which there are no data will always give a value of zero for the weight.