Chemestry Test 1
Which one of the following is the softest?
  • Aluminium
  • Iron
  • Lithium
  • Sodium
Explanation: Sodium is indeed the softest metal among the options listed. Sodium is a soft, silvery-white, highly reactive metal that can be easily cut with a knife. It's softer than lithium, aluminum, and iron.
Salts of which of the following elements provide colours to fireworks?
  • Chromium and nickel
  • Strontiurn and barium
  • Potassium and mercury
  • Zinc and sulphur
Explanation: Strontium salts (like strontium carbonate) produce red colors in fireworks. Barium salts (like barium nitrate) produce green colors in fireworks. These elements are commonly used to create vibrant colors in pyrotechnics.
In which type of rocks are metals like Gold and Copper mostly found?
  • New metamorphic
  • Old metamorphic
  • Old sedimentary
  • Old igneous
Explanation: Metals like gold and copper are primarily found in old igneous rocks, which form from the cooling and solidification of molten magma. These metals often accumulate in veins or deposits within these rocks over geological time periods.
The vinegar is a solution of
  • 5% acetic acid in water
  • 10% acetic acid in water
  • 15% acetic acid in water
  • 50% acetic acid in wate
Explanation: Vinegar typically contains around 5% acetic acid by volume, with the remainder being water. It is used as a condiment, preservative, and in cooking for its tangy flavor.
In coloured galss. the purple colour is imparted by
  • Manganese oxide
  • Cadmium sulphide
  • Ferric oxide
  • Selenium sulphide
Explanation: Manganese oxide is commonly used to impart a purple color to glass. It works as a decolorizer in glass production, and depending on the quantity used, it can produce shades of purple or violet.
The quantum theory was first enunciated by
  • Max Born
  • Max Planck
  • Albert Einstein
  • Niel Bohr
Explanation: Max Planck is credited with formulating the quantum theory in 1900. He introduced the concept of "quanta" to explain blackbody radiation, which laid the foundation for quantum mechanics.
Which of the following is not a source of sulphur?
  • Cinnabar
  • Explanation: Carnalite is not a source of sulfur. It is a potassium magnesium chloride sulfate mineral, and while it contains sulfur in its sulfate component, it is not primarily considered a source of sulfur.