Question

Rubidium and caesium are pyrophoric. Here the term pyrophoric means:

• A. that hardly catches fire
• B. that does not catches fire at all
• C. that catches fire spontaneously
• D. none of these

Answer 1

The correct option is C that catches fire spontaneously

Pyrophoric means liable to ignite spontaneously on exposure to air. It means it will catch fire spontaneously when exposed to air.