Which allotrope of phosphorus does not catch fire easily?

To which group does chlorine element belong?

Phosphine is prepared from which of the following methods?

Which oxide of nitrogen is released from car engines?

Which of the following does not react with hydrochloric acid to give chlorine as a product?

What is the half-life of radon?

If a aryl diazonium salt is treated with sulfur dioxide, what product forms?

What is the transition temperature of alpha- and beta-sulfur?