Which one of the following metals burns, if kept in air?

• Magnesium
  
  

• Aluminum
  
  

• Zinc
  
  

• Sodium

Which one of the following gases burn with pop sound?

• Hydrogen

• Nitrogen dioxide
  
  

• Sulphur dioxide
  
  

• Oxygen
  
  

Which one of the following metals is not a mineral?

• Bauxite
  
  

• Gypsum
  
  

• Hematite
  
  

• Limonite

4.

Which one of the following non-metals is liquid?

• Iodine
  
  

• Sulphur
  
  

• Bromine
  
  

• Phosphorus

Which scientist discovered the radioactive element radium?

• Albert Einstein
  
  

• Benjamin Franklin
  
  

• Isaac Newton
  
  

• Marie Curie

The gas used in artificial ripening of green fruits is

• ethane
  
  

• hydrogen
  
  

• acetylene
  
  

• nitrogen

Ozone is

• an allotrope of oxygen
  
  

• an isomer of oxygen
  
  

• a compound of oxygen
  
  

• an isotope of oxygen

Brine' is

• Common name of bleaching powder
  
  

• aqueous solution of chlorine
  
  

• saturated solution of NaCl
  
  

• aqueous solution of Na₂SO₄

Which of the following has maximum number of atoms?

• 16 g N₂

• 16 g of CO₂

• 16 g of CH₄

• 16 g of O₂

In laboratory, ethylene and acetylene can be distinguished by

• Br₂/H₂O

• KMnO₄/OH/H₂O

• Tollens' reagent

• Fehling solution