Which non-metal element exists in a liquid state at room temperature?

Which of the following ores is in the form of oxide?

In the $Hall-Heroult$ process,which substances are added to alumina to lower its melting point?

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be:

What effect does dihydrogen gas $(H_2)$ have on litmus paper?

When sulfur dioxide gas reacts with hydrogen sulfide gas,sulfur is formed. Which of the following statements about sulfur dioxide is incorrect for this reaction?