Question

Which element is most poisonous to humans?
A.$\text{O}$
B.\[\text{S}\]
C.\[\text{Se}\]
D.None of the above

Answer 1

Hint:An element becomes poisonous to the body when it either attacks the central nervous system of the body or stops the blood flow to the different parts of the body.

Complete step by step solution:
Out of the 118 elements discovered so far, there are some elements that have proved to be very dangerous to the human body.
$\text{O}$ – Oxygen is the most necessary element for the human body, without which the survival of the animals and human beings would not have been possible. It is a constituent of almost all the compounds that are required by us to survive. So this element cannot be dangerous.
\[\text{S}\] - Sulphur forms the basic unit in two of the essential amino acids that are required by human beings. Hence this also cannot be dangerous to the human body.
\[\text{Se}\] – Selenium is essential in trace quantities in the human bodies for normal cellular functions and is required for good health, especially for glowing skin and strong bones. So this cannot be poisonous to our bodies, unless present in excess quantities.
Hence the correct option is none of the above.

Hence, option D is correct.

Note:
The elements that are most dangerous to the human bodies include: plutonium, polonium, mercury, and chromium in the hexavalent state, arsenic, fluorine, lead, chlorine, and few more. The radioactive metal polonium was the reason for the death of Madam Curie.